A method is described for producing n-propyl bromide of a high degree of purity, which contains isopropyl bromide in an amount lower than 0.1% w/w, and usually lower than 0.05%. The method is characterized in that n-propanol is reacted with HBr which is in gas form, preferably dry, and which is in excess over the stoichiometric amount, wherein the excess HBr is at the end of the reaction in an aqueous solution formed from the reaction water. The invention further relates to N-propyl bromide of high purity, containing typically less than 500 ppm of isopropyl bromide.

N-propyl bromide is a product which has considerable industrial importance, particularly as a solvent for cleaning and degreasing replacing ODS (such as: 1,1,1-TCE, CFC-113) used in precision cleaning electronic defluxing, metal cleaning, adhesives, coatings, products and solvent applications.
In principle, n-propyl bromide is the product of a reaction between hydrobromic acid HBr and n-propanol. However, depending on the way in which the reaction is carried out, the result may be unsatisfactory, e.g., as to conversion and purity of the product, and most particularly, because of the contamination with by-products, especially isopropyl bromide.
Schematically, the reaction is as follows:HBr+CH3—CH2—CH2OH→CH3—CH2—CH2Br+H2O.
In prior art processes, the n-propyl bromide form contains a weight percentage of isopropyl bromide which may approach and even exceed 1%. (All the percentages in this specification and claims are by weight, unless otherwise indicated.) Said percentage is higher than desirable, because isopropyl bromide has a proven toxic effect, and it is a purpose of this invention to provide a process for the preparation of n-propyl bromide from HBr and n-propanol wherein the resulting n-propyl bromide contains amounts of isopropyl bromide equal or below 0.1%, preferably equal or below 0.05%, viz. equal or below 500 ppm.
It is another purpose of this invention to provide such a process which can be carried out continuously or in batch procedure.
It is a still further purpose of this invention to provide such a process which has a high conversion rate.
Other purposes and advantages of this invention will appear as the description proceeds.

Method for the preparation of n-propyl bromide


An energy content meter can spectroscopically quantify oxidation products after oxidation of a combustible mixture. The measured oxidation product concentrations or mole fractions can be converted to an energy content of the un-oxidized combustible mixture using a conversion factor that relates oxygen consumption during oxidation of the combustible mixture to the energy content of the combustible mixture.

Determining the energy content of mixtures containing hydrocarbons and other organic compounds can be important in a number of applications. Energy feedstocks, such as natural gas, liquid natural gas, crude and refined petroleum products, and the like may be valued and traded based on the energy content of the mixture. Even small offsets in the energy content (or BTU) value of the mixture can potentially translate to significant energy value differences. For example, in natural gas pipelines, very large quantities of hydrocarbon mixtures having variable composition are transported over very short periods. The energy density of natural gas is typically desirably maintained at or near 1050 BTU/ft3 to ensure proper, energy efficient operation of turbines, furnaces, and other combustion systems and to reduce the potential for damage to equipment. Non-optimized operation can create excessive CO and CO2, due to under efficient energy extraction and can also create costly damage to power generation turbines. Real time or near real-time BTU measurement of the turbine feeding gas stream is essential to prevent equipment damage and minimize emission of CO and CO2.
Energy content measurements for a mixture can be performed with a calorimeter. For this technique, a mixture to be analyzed is fed to a calorimeter chamber at a known, constant rate to a jet at which the reaction occurs. Alternatively, a known volume of the mixture is analyzed in a batch manner. The reaction chamber and gas pipes are contained in a thermostatically controlled water bath to ensure constant temperature. The reaction is then started and the temperature rise measured after a known amount of gas has been fed into the reaction. Calibration of the calorimeter, either with a standard reaction or by electrical means, allows calculation of the enthalpy (ΔH) of the reaction because the reaction is conducted at constant pressure. Flame calorimetry can be performed in near real time depending on the design of the device employed. However, if the heated mass has a large heat capacity, it will take longer to register a meaningful temperature shift which can result in a delay. Ambient heat loads can also introduce potential measurement delays and/or errors. In addition, calorimeter design is very difficult, especially for processes involving very small energy changes, e.g., energy changes on top of a large background such as pipeline gas. Maintenance and calibration of these devices can also require considerable resources.
Analyzers which calculate energy content by measuring residual oxygen left over from combustion of the gas provide indirect measurements that can also be susceptible to various errors. For example, oxygen can be consumed in the formation of nitrogen oxides from N2 present in the mixture being tested, which can lead to over-estimation of the energy content. Furthermore, oxygen probes used in such sensors can be limited in their sensitivity and can have operating temperature limitations that could prevent their use in pyrolysis ovens. Cooling and further handling can also be required, thereby leading to additional analytical errors. Use of paramagnetic oxygen sensors can also limit the operating temperature and resolution. Incomplete oxidation of the mixture can lead to additional errors. The use of an oxygen stream for the oxidation can also lead to increased operating costs.
Sampling of the mixture composition by gas chromatography (GC) can be used to separate and quantify each species that is present. However, gas chromatography can have difficulty speciating compounds with 5 or 6 to 10 or more carbon atoms and can be susceptible to interference by contaminants such as water, sulfur compounds, and other mixture components that can foul the GC column. Additionally, GC measurements can take several minutes or even longer per sample. At pipeline pressures and transport speeds typical for natural gas, this delay can potentially lead to substantial billing errors, on the order of thousands of dollars. Gas chromatography also cannot determine the hydrogen concentration of a gas stream, so the total energy content can potentially be under-represented by such a measurement. Operation and maintenance costs of operating GCs can also be quite large due to the required consumable carrier gases and the regular maintenance required to assure that the instrument will continue to provide accurate data.

Energy meter for mixed streams of combustible compounds


Methods of fabricating perpendicular write elements for perpendicular magnetic recording heads are discussed. In write element fabrication, write poles are fabricated according to one of many desired methods. The write poles during fabrication are typically covered by a hard mask and a photolithographic soft mask. According to the methods described herein, the soft mask is removed such as by chemical etching. The hard mask is then removed, such as by CMP and ion etching, to expose the write poles. Shield gap material may then be deposited on the write poles to define the shield gap between the write poles and the trailing shields. Trailing shield material may then be deposited on the shield gap material to form the trailing shields corresponding with the write poles.

1. Field of the Invention
The invention is related to the field of recording head fabrication and, in particular, to improved methods of fabricating perpendicular write elements in perpendicular magnetic recording heads. More particularly, improved methods are discussed to form the write pole and the trailing shield of a perpendicular write element.
2. Statement of the Problem
Magnetic disk drive systems typically include a magnetic disk, a recording head having write and read elements, a suspension arm, and an actuator arm. As the magnetic disk is rotated, air adjacent to the disk surface moves with the disk. This allows the recording head (also referred to as a slider) to fly on an extremely thin cushion of air, generally referred to as an air bearing. When the recording head flies on the air bearing, the actuator arm swings the suspension arm to place the recording head over selected circular tracks on the rotating magnetic disk where signal fields are written to and read by the write and read elements, respectively. The write and read elements are connected to processing circuitry that operates according to a computer program to implement write and read functions.
Magnetic disk drives have typically been longitudinal magnetic recording systems, wherein magnetic data is recorded as magnetic transitions formed longitudinally on a disk surface. The surface of the disk is magnetized in a direction along a track of data and then switched to the opposite direction, both directions being parallel with the surface of the disk and parallel with the direction of the data track.
Unfortunately, data density requirements are fast approaching the physical limits. Overall data density (or areal density) may be improved by improving linear density and/or track density. To improve linear density, bit sizes on a track need to be reduced which in turn requires decreasing the grain size of the magnetic medium. As this grain size shrinks, the magnetic field required to write a bit of data increases proportionally. The ability to produce a magnetic field strong enough to write a bit of data using conventional longitudinal write head technologies is reaching its physical limit.
One way to achieve higher density recordings is with perpendicular recording. In perpendicular recording systems, bits of data are recorded magnetically perpendicular to the plane of the surface of the disk. The magnetic disk may have a relatively high coercivity material at its surface and a relatively low coercivity material just beneath the surface. A write pole having a small cross section and very high magnetic flux emits a strong, concentrated magnetic field perpendicular to the surface of the disk. This magnetic field emitted from the write pole is sufficiently strong to overcome the high coercivity of the surface material and magnetize it in a direction perpendicular to its surface. The magnetic flux then flows through the relatively soft underlayer (SUL) and returns to the surface of the disk at a location adjacent to a return pole of the perpendicular write element. The return pole of the write element typically has a cross section that is much larger than that of the write pole so that the magnetic flux through the disk at the location of the return pole (as well as the resulting magnetic field between the disk and return pole) is sufficiently spread out to render the magnetic flux too weak to overcome the coercivity of the disk surface material. In this way, the magnetization imparted by the write pole is not erased by the return pole.
FIG. 1 illustrates a typical perpendicular write element 100 adapted to write to a perpendicular magnetic recording medium 120. Write element 100 generally includes a yoke 101 comprising a write pole 102 and a return pole 104. Write element 100 also includes a coil wrapped around yoke 101 that is not shown. Perpendicular recording medium 120 includes a perpendicular magnetic recording layer 122 and a soft underlayer (SUL) 124.
When in operation, perpendicular recording medium 120 spins from left to right in FIG. 1. A magnetic flux is generated in yoke 101 due to an electrical current flowing through the coils (not shown). The magnetic flux flows through write pole 102, and write pole 102 emits a magnetic field across the write gap into perpendicular recording medium 120. The magnetic flux then flows through the SUL 124 and returns to the surface of the disk at a location adjacent to return pole 104. As the magnetic field passes through perpendicular magnetic recording layer 122, the perpendicular component of the magnetic field influences the magnetization orientation of the perpendicular magnetic recording layer 122 in the direction of the magnetic field. The magnetization orientations of three bits in perpendicular magnetic recording layer 122 are illustrated as single arrows pointing up or down in FIG. 1.
When write element 100 is writing to perpendicular recording medium 120, write pole 102 has a leading side 106 and a trailing side 107. To prevent writing to neighboring bits along the track, a trailing shield 108 may be added proximate to the trailing side 107 of write pole 102. The separation between the trailing shield 108 and the write pole 102 is referred to as the shield gap. Trailing shield 107 shunts unwanted magnetic flux from write pole 102.
FIGS. 2-3 illustrate a method 200 of fabricating write poles and trailing shields for perpendicular write elements. FIG. 2 is a flow chart illustrating the method of fabricating, while FIG. 3 illustrates the results of method 200 in forming the layers of the write poles, the trailing shields, etc. Although method 200 described in FIG. 2 applies to wafer-level fabrication, FIG. 3 shows the results for a single perpendicular write element being fabricated on a wafer (not shown). The reference numbers of the steps shown in FIG. 2 are also referenced in FIG. 3.
In step 201, write pole material 301 is deposited (e.g., NiFe, CoNiFe, CoFe, or laminated CoFe/Cr) on the wafer. In step 202, a hard mask 302 is deposited on the write pole material 201. The hard mask 302 may comprise a Thin Alumina Mask (TAM). In step 203, photolithographic soft masks 303 are formed on the hard mask 302 corresponding with the locations of the write poles through deposition and patterning steps. In step 204, ion milling or another similar process is performed on the wafer to remove the write pole material 301 and the hard mask 302 not covered by the soft masks 303. After step 204, write poles 304 remain covered by the hard mask 302 and the soft mask 303. At this point, there may be a targeted re-deposition of the write pole material 301 on the sides of the write pole 304 to achieve a desired shape of the write pole 304. In FIG. 3, the top surface of the write pole 304 comprises the trailing side of the write pole, which is shown as surface 107 in FIG. 1.
In step 205, insulating material 305 (e.g., aluminum oxide) is deposited over the write poles 304, the hard mask 302, and the soft masks 303. In step 206, chemical mechanical polishing (CMP) is performed to a desired depth, which removes some of the insulating material and the soft masks 303. After CMP, notches 306 remain on top of the hard mask 302. In step 207, trailing shield material 307 is deposited to form the trailing shields 308.
One problem with conventional methods of fabrication such as described above is that control of the shield gap between the write pole 304 and the trailing shield 308 may not be as precise as desired. In this fabrication process, the hard mask 302 remains between the write pole 304 and the trailing shield 308. Thus, the thickness of the hard mask 302 defines the shield gap, which may not be as precisely controlled during fabrication as desired.

Fabricating perpendicular write elements in perpendicular magnetic recording heads

Hitachi Global Storage Technologies Netherlands, B.V.


A prismatic optical device employs an improved prismatic image erecting system with curved refracting surfaces. The optical device can be any one of a wide variety of known devices such as telescopes and binoculars which include an objective, an image erecting system and an ocular. The erecting prism of the optical system is preferably an integral prism formed of optical quality plastic and may comprise a Porro erecting prism system or an image erecting system employing pentangular or roof prisms.

1. Field of the Invention
The present invention generally relates to the field of optics and particularly to the field of prismatic optical devices. More specifically, the present invention pertains to optical devices such as telescopes and binoculars employing prismatic image erecting systems. Accordingly, the general objects of the present invention are to provide novel and improved apparatus of such character.
2. Description of the Related Art
Optical devices employing image erecting systems are well known in the art. Such devices typically utilize an objective and an ocular in cooperation with the erecting system to present a magnified image of an object to a viewer. Astronomical telescopes, terrestrial telescopes and prism binoculars are but a few examples of such devices. Image erecting systems are needed in such devices to reverse and invert, i.e., rectify in directions both parallel to and perpendicular to, the image formed by the objective since the objective inherently reverses and inverts images as light passes therethrough. However, the use of image erecting systems necessarily yields the undesirable result that four times the focal length of the erecting lens must be added to the sum of the focal lengths of the objective and ocular in order to present a sharp image to a user's eye. In the case of terrestrial telescopes this results in an unduly long draw tube.
This deficiency has conventionally been overcome in a number of ways, all of which employ the phenomenon of total internal reflection to reflect light rays passing therethrough to reverse and invert the image produced by the objective. According to a first solution, the image erecting system can be comprised of a pair of 45.degree.-45.degree.-90.degree. triangular prisms (hereinafter "Porro prisms") wherein the hypotenuse of each triangular prism faces one another and wherein the prisms are oriented at right angles to one another. This erecting system configuration is known as a "Porro prism erecting system." The deficiencies associated with such Porro prism erecting systems include the fact that each of the Porro prisms used therein have, in the past, been formed of a separate piece of expensive Crown glass with a refractive index larger than 1.5 using an expensive three step process of blocking, grinding and polishing. Further, in an attempt to minimize manufacturing costs, the size and shape of the prisms are often not optimized to the dimensions of the light ray cone expectedly incident thereto. This results in the existence of non-ray path areas of the prisms which serve no useful purpose but do have the undesirable effect of enlarging the overall size of the optical device.
Another deficiency of the Porro prism erecting systems of the related art arise from the need to mechanically mount the prisms within the optical device. Such mounting inevitably results in, at least, a small gap existing between the two prisms. This gap is responsible for light transmission losses (usually of about 8%) and polarization, chromatic and spherical aberrations at the surfaces of both hypotenuses. While polarization aberration and light reflection losses can be reduced by depositing expensive optical coatings between the prisms, this further increases costs. Furthermore, chromatic and spherical aberrations cannot be so rectified. Thus, additional lenses have been required to correct such defects. Finally, even assuming the presence of such a gap can be tolerated, the need to ensure precise alignment between the Porro prisms of the erecting system further increases the cost and difficulty of assembling such optical devices.
A second way to avoid the deficiency of utilizing an unduly long draw tube in an optical device employing an image erecting system is to form the image erecting system from a pair of pentangular roof prisms, also known as Amici prisms or ridge glass prisms. Aside from possessing most of the deficiencies noted above, the use of such image erecting systems entails bearing the additional expense of utilizing expensive jigs and other tools to manufacture the odd-shaped roof prisms and incurring additional assembly costs.
A final way to avoid the deficiency of utilizing an unduly long draw tube in such optical devices is to form the image erecting system from reflecting mirrors which are arranged in a prism-like form. While this solution can be somewhat less expensive than the above-noted solutions (due to the relatively low cost associated with producing the mirrors), any mirror misalignment which may exist will introduce errors the magnitude of which are multiplied up to four times as light passes through the erecting system and into the ocular. Thus, even small positional errors can lead to significant image distortion.
Therefore, there remains a need in the art for an optical system with an improved image erecting system which reduces light transmission losses as well as polarization, chromatic and spherical aberrations thereby minimizing the number of lenses necessary to form a high quality optical device.
There remains an additional need in the art for an optical system with an improved image erecting system which offers improved performance while reducing material, component-manufacturing and assembly costs.
There remains a further need in the art for an optical system with an improved image erecting system which offers an optimal combination of simplicity, economy, precision and versatility.


This invention relates to data backup and data recovery in a computer system. An outputting unit updates data stored in a first area based on an update request of data from the host computer, a creating unit stores update data for the update request in a second area, a marker processing unit creates a marker containing information of the range, in which the data is stored, and information indicating whether or not the data is allowed to be stored in a third area based on a request of creating the marker from the host computer to store the created marker in the second area, and a reflecting unit refers to the marker, obtains the update data corresponding to the data storing range, which is stored prior to the marker, and reflects the obtained update data to the third area.

This invention relates to data backup and data recovery for a computer system.
In order to reduce the risk of losing data stored in a storage system due to a disaster or a failure, a method of creating and storing a copy of the data stored in the storage system is known. As techniques of creating a copy, there are a backup and restore technique and a remote copy technique, both using a journal.
For example, the following technique is known as the backup and restore technique using a journal. In other words, a storage system maintains a journal of a plurality of journal entries and at least one snapshot of one or more data volume. By assigning a unique sequence number to each of the journal and the snapshot in the order of occurrence, it becomes easy to find out a journal to be applied to the snapshot. In this manner, an overflow condition causing the exhaustion of a journal space is detected to recover the journal space, as described in JP 2005-18738 A.
The following technique is known as the remote copy technique using a journal. In other words, at least two secondary storage systems are connected to a primary storage system connected to an upstream device. The secondary storage systems read out journals of data update from the primary storage system at their own timings so as to save the read journals in predetermined logical volumes. Then, the secondary storage systems create copies of the data in the primary storage system based on the journals stored in the virtual volumes at their own timings so as to store the copies in secondary virtual volumes. The primary storage system retains the journals until both the secondary storage systems read and restore the journals. The timing of journal read is controlled according to the quantity of journals, a processing load and the like, as described in JP 2005-174196 A.

Storage system with journal reflecting area control function


A fuel cell stack assembly includes first and second bipolar plates, an active area membrane, and an optional subgasket. The first bipolar plate defines a first plurality of tunnels and the second bipolar plate defines a second plurality of tunnels. The second plurality of tunnels may be engaged with and nested between the first plurality of tunnels. The active area membrane may be disposed within an internal periphery of a subgasket between the first and second bipolar plates wherein the subgasket may, optionally, be positioned between the first and second plurality of tunnels.

Fuel cells have been used as a power source in many applications. For example, fuel cells have been proposed for use in electrical vehicular power plants to replace internal combustion engines. In proton exchange membrane (PEM) type fuel cells, hydrogen is supplied to the anode of the fuel cell and oxygen is supplied as the oxidant to the cathode. PEM fuel cells include a membrane electrode assembly (MEA) comprising a thin, proton transmissive, non-electrically conductive, solid polymer electrolyte membrane having the anode catalyst on one face and the cathode catalyst on the opposite face. The MEA is sandwiched between a pair of non-porous, electrically conductive elements or plates which (1) pass electrons from the anode of one fuel cell to the cathode of the adjacent cell of a fuel cell stack, (2) contain appropriate channels and/or openings formed therein for distributing the fuel cell's gaseous reactants over the surfaces of the respective anode and cathode catalysts; and (3) contain appropriate channels and/or openings formed therein for distributing appropriate coolant throughout the fuel cell stack in order to maintain temperature.
The term "fuel cell" is typically used to refer to either a single cell or a plurality of cells (stack) depending on the context. A plurality of individual cells are typically bundled together to form a fuel cell stack and are commonly arranged in electrical series. Each cell within the stack includes the membrane electrode assembly (MEA) described earlier, and each such MEA provides its increment of voltage. A group of adjacent cells within the stack is referred to as a cluster. By way of example, some typical arrangements for multiple cells in a stack are shown and described in U.S. Pat. No. 5,663,113. In PEM fuel cells, hydrogen (H2) is the anode reactant (i.e., fuel) and oxygen is the cathode reactant (i.e., oxidant). The oxygen can be either a pure form (O2) or air (a mixture of O2 and N2).
The electrically conductive plates sandwiching the MEAs may contain an array of grooves in the faces thereof that define a reactant flow field in the active area region for distributing the fuel cell's gaseous reactants (i.e., hydrogen and oxygen in the form of air) over the surfaces of the respective cathode and anode. Tunnels are also defined in the region between the manifold inlets/outlets and the active area region. Coolant tunnels are provided to route coolant fluid between the coolant inlet/outlet and the flow field in the active area region. Reactant tunnels are provided to route each reactant from the particular reactant inlet to the flow field and to also route each reactant from the flow field to the particular reactant outlet. These tunnels are generally a plurality of flow channels through which the gaseous reactants and/or coolant flow from a supply header at one end of the flow channels to an exhaust header at the opposite end of the flow channels. The reactant flow field is a predetermined flow field pattern defined in each of the anode half and the cathode half of the adjacent bipolar plates which are directly adjacent to a face of the gas diffusion layer in order to encourage a reaction therebetween.
In a fuel cell stack, multiple fuel cells are stacked together in electrical series while being separated by gas impermeable, electrically conductive bipolar plates. In some instances, the bipolar plate is an assembly formed by securing a pair of thin metal sheets (in the form of an anode half and a cathode half) wherein each sheet/half defines reactant flow fields formed on their external face surfaces. When the thin metal sheets (anode half and cathode half) are joined together, tunnels for the coolant and reactant fluids are defined between the thin metal sheets. Typically, an internal coolant flow field is provided between the metal plates of each bipolar plate in the fuel cell stack. It is also known to locate a spacer plate between the metal plates to optimize the heat transfer characteristics for improved fuel cell cooling.
Typically, the cooling system associated with a fuel cell stack includes a circulation pump for circulating a liquid coolant through the fuel cell stack to a heat exchanger where the waste thermal energy (i.e., heat) is transferred to the environment. The thermal properties of typical liquid coolants require that a relatively large volume be circulated through the system to reject sufficient waste energy in order to maintain the temperature of the stack within an acceptable range, particularly under maximum power conditions.
A common type of fuel cell is known as a proton exchange membrane (PEM) fuel cell. The PEM fuel cell includes a unitized electrode assembly (UEA) disposed between a pair of fuel cell plates such as bipolar plates, for example. The UEA may include diffusion mediums (also known as a gas diffusion layer) disposed adjacent to an anode face and a cathode face of a membrane electrolyte assembly (MEA). The MEA includes a thin proton-conductive, polymeric, membrane-electrolyte having an anode electrode film formed on one face thereof, and a cathode electrode film formed on the opposite face thereof. In general, such membrane-electrolytes are made from ion-exchange resins, and typically comprise a perfluoronated sulfonic acid polymer such as NAFION™ available from the E.I. DuPont de Nemeours & Co. The anode and cathode films, on the other hand, typically comprise (1) finely divided carbon particles, very finely divided catalytic particles supported on the internal and external surfaces of the carbon particles, and proton conductive material (e.g., NAFION™) intermingled with the catalytic and carbon particles, or (2) catalytic particles, sans carbon, dispersed throughout a polytetrafluoroethylene (PTFE) binder.
As indicated, the MEA may be sandwiched between sheets of porous, gas-permeable, conductive material ("gas diffusion layer") in which a gas diffusion layer presses against each of the anode and cathode faces of the MEA. Suitable such primary current collector sheets or gas diffusion mediums may comprise carbon or graphite paper or cloth, fine mesh noble metal screen, and the like, as is well known in the art.
The formed-sandwich is pressed between a pair of electrically conductive plates (hereinafter referred to as "bipolar plates") which serve as secondary current collectors for collecting the current from the primary current collectors and conducting current between adjacent cells (i.e., in the case of bipolar plates) internally of the stack, and externally of the stack in the case of monopolar plates at the ends of the stack. As previously indicated, the bipolar plates each define dedicated tunnels for the coolant fluid and for each reactant fluid in addition to at least one so-called "flow field" which distributes the fuel cell's gaseous reactants (e.g., H2 and O2/air) over the surfaces of the anode and cathode. Tunnels 118, 118′, 168, 168′ route each of the reactant fluids and the coolant fluid from each corresponding manifold inlet to the flow field. Serpentine flow channels may, but not necessarily, be used in the flow field wherein a number of hairpin turns and switch backs may be defined such that each leg of the serpentine flow channel borders at least one other leg of the same serpentine flow channel.
Similarly, proximate to the manifold apertures which function as outlets, the tunnels are configured to route each of the reactant product fluids and the coolant fluid from the flow field to the manifold apertures which function as outlets. With reference to FIG. 1, it is understood that the tunnels 118 may be tunnels dedicated to one of two specific reactant inlets (if tunnels 118 are disposed between a reactant inlet/outlet and the flow field)—such that tunnels 118 route a reactant fluid to/from a reactant inlet to the flow field. Similarly, coolant tunnels 168 may be provided in a region (in lieu of reactant tunnels) when the tunnels 168 are disposed between a coolant inlet and the flow field—such that the tunnels 168 route a coolant fluid to/from an outlet/inlet of the coolant to the flow field. However, regardless of whether the tunnels are coolant tunnels 168 or reactant tunnels 118, it is understood that the tunnels 118, 118′, 168, 168′ (shown in FIG. 1) are traditionally stacked directly upon each other (with the subgasket in between 130) as shown in FIG. 1.
Therefore, in FIG. 1, a traditional arrangement is shown wherein a first bipolar plate 114 is formed from elements 156, 158 while the second bipolar plate 116 is formed from elements 156′, 158′ with a subgasket 130 disposed between the two bipolar plates 114, 116. Where the tunnels in FIG. 1 are reactant tunnels 118, 118′, it is understood that reactant tunnels 118, 118′ for the first and second bipolar plates respectively are stacked directly on top of each other. However, where the tunnels in FIG. 1 are coolant tunnels 168, 168′, the tunnels 168, 168′ are also stacked directly on top of each other. It is understood that reactant gases 131, 133 may flow through reactant tunnels 118, 118′ when the tunnels are located between the flow field and the manifold inlets/outlets. Accordingly, under this traditional arrangement, the overall length 194 as shown in FIG. 1 may be defined by the distance which spans an anode plate half, a cathode plate half, and a UEA disposed therebetween. The overall length 194 is generally referred to as the cell repeat distance. As a result, the overall length across each fuel cell is dependent on the stacked configuration wherein each coolant tunnel 168 is stacked directly above or below another coolant tunnel 168′.
However, it is desirable in the industry to reduce the overall size of the fuel cell stack while improving the flow capabilities for all three fluids (e.g. H2, O2/air, and coolant) at each bipolar plate.


Techniques are described for writing commands to memory units of a chain of memory units of a command buffer. The techniques may write the commands, and if during the writing, it is determined that there is not sufficient space in the chain of memory unit, the techniques may flush previously confirmed commands. If after the writing, the techniques determine that there is not sufficient space in an allocation list for the handles associated with the commands, the techniques may flush previously confirmed commands.

Visual content for display, such as content for graphical user interfaces and video games, may be generated by a graphics processing unit (GPU). A GPU may convert two-dimensional (2D) or three-dimensional (3D) graphical objects into a 2D pixel representation that may be displayed on a display device. To perform its functions, the GPU executes commands issued by an application processor such as the central processing unit (CPU). In general, the CPU stores the commands in a command buffer, and the GPU retrieves the commands from the command buffer for execution.


A lens barrel capable of shortening its full length includes a photo-taking optical system with a rear unit lens and a front unit lens, a rear unit lens holding cylinder holding the rear unit lens, a front unit lens holding cylinder holding the front unit lens and movable in the direction of an optical axis relative to the rear unit lens between a photographing position for making the photo-taking optical system capable of photographing with the rear unit lens and a full length shortening position for shortening the full length of the lens barrel in the direction of the optical axis and a fixing member for fixing the front unit lens holding cylinder in one of the aforementioned positions relative to the rear unit lens holding cylinder.

1. Field of the Invention
This invention relates to a collapsible lens barrel suitable for use in a camera.
2. Related Background Art
Heretofore, a lens barrel of this kind has had its full length in the direction of its optical axis shortened (hereinafter referred to as "collapsing") during non-photographing to thereby improve the portability of the lens barrel. Generally, there are two kinds of methods of effecting the collapsing of a lens barrel.
A first method is a method of separating a lens barrel into a mounting portion for a camera body and a barrel portion. The barrel portion is mounted on the camera body in the mounting portion, and the barrel portion is slidable in the direction of the optical axis relative to the mounting portion. During photographing the barrel portion is disposed so as to protrude forwardly of the lens (forwardly of the optical axis), and during non-photographing the barrel portion is retracted to the interior of the camera body, whereby collapse is effected.
A second method is a method used in a zoom lens barrel or the like, and the operation range of an operating ring for driving a zoom lens unit is extended rearwardly of the optical axis. When collapsing is to be effected in this method, the zoom lens unit is moved rearwardly of the optical axis usually beyond a photographing range to thereby shorten the full length of the lens barrel.
However, lens barrels using the above-described conventional collapsing methods have suffered from the following problems.
In a lens barrel using the first collapsing method, if it is a lens barrel equipped with only a function independent on a camera body such as manual focusing or a preset aperture, it is relatively easy to effect its design and manufacture. However, in the case of a lens barrel equipped with the auto focusing function and an automatic aperture mechanism which are now more popular, the presence of an aperture transmitting member and an auto focus drive force transmitting mechanism connected to the camera body side prevents the lens barrel from being simply separated into a mounting portion and a barrel portion. This has led to the problem that the design and manufacture of the lens barrel are difficult.
Also, there are a mirror and others in the camera body and the lifting or the like of the mirror is effected in advance by a discrete mechanism provided on the camera body side, whereafter it is required to retract the barrel portion into the camera body. However, if in the case of lens interchange, the mirror lifting operation is not effected from carelessness, the barrel portion in its collapsed state will strike against the mirror or the internal mechanism of the body and lens interchange will not be effected smoothly. If in contrast, design is made such that the lifting of the mirror takes place automatically during lens interchange, it has led to the problem that the mechanism on the camera body side will become very complicated.
On the other hand, in the case of a lens barrel using the second collapsing method, it is possible to effect collapse only within a range in which a zooming lens unit or the like can be rearwardly retracted. Accordingly, this has led to the problem that in a lens barrel wherein a fixed lens unit is arranged long in the direction of the optical axis, there is a limit to the shortening of the full length of the lens barrel by collapsing.


To provide a new technique by which efficient transfection is ensured in delivering a target gene into a cell, disclosed is a nucleic acid construct for nuclear import, which comprises a ternary complex consisting of a nucleic acid substance containing a gene to be delivered into the nucleus of a cell, an importin protein (for example, importin-β) capable of passing through the nuclear pore and involved in the nuclear transport, and a binding substance (for example, polyethyleneimine) bound to both of the nucleic acid substance and the importin protein. Nucleic acid transport from outside of a cell into the cell nucleus can be particularly promoted by administering the nucleic acid construct bound to a cell membrane receptor binding factor and/or a membrane fusing substance, or administering the nucleic acid construct encapsulated in a non-viral vector (for example, Sendai virus envelope) having cell membrane permeability and membrane fusing properties.

Transfection, a process for delivering an exogenous specific gene into cells, is an indispensable way for obtaining useful information for the treatment of diseases and the development of medicines, by analyzing the action mechanism in which the gene is involved. In such transfection, trials have been recently made to use non-viral effects in order to avoid harmful effects upon the organism. It has been pointed out that there are big barriers to the improvement of transfection efficiency with a non-viral vector, including the passage through the cytomembrane, the escape from transport vesicles, the nuclear import, and the DNA release of a nucleic acid until the nucleic acid is lead to the transcription reaction.    Non-patent reference 1: MarShall, E. (1999) Science 286, 2244-2245.    Non-patent reference 2: Hacein-Bey-Abina, S., Von Kalle, C., Schmidt, M., McCormack, M. P., Wulffrat, N., Leboulch, P., Lim, A., Osborne, C, S., Pawliuk, R., Morillion, E., Sorensen, R., Forster, A., Fraser, P., Cohen, J. I., de Saint Basile, G., Alexander, I., W intergerst, U., Frebourg., T., Aurias, A. D., Stoppa-Lyonnet, D., Romana, S., Radford-Weiss, I., Gross, F., Valensi, F., Delabesse, E., Macintyre, E., Sigaux, F., Soulier, J., Leiva, L. E., Wissler, M., Prinz, C., Rabbitts, J., Le Deist, F., Fischer, A., and Cavazzana-Calvo M. (2003) Science 302, 415-419.    Non-patent reference 3: Huang, L., Hung, M.-C., and Wagner E. (1999) Nonviral Vectors for Gene Therapy, AcademicPress, San Diego.    Non-patent reference 4: Rolland, A (1999) Advanced Gene Delivery, Harwood Academic Publishers, Amsterdam.    Non-patent reference 5: Wiethoff, C. M., and Middaugh, C. R. (2003) J. Pharm. Sci., 92, 203-217.
As a way to improve the cytomembrane passage, utilization of cell membrane receptor-binding factors has been studied, and an improvement is seen via the receptor-mediated endocytosis.    Non-patent reference 6: Vyas S P, Singh A. Sihorkar V. (2001) Crit Rev Ther Drug Carrier Syst., 18(1), 1-76.
Most of non-viral vectors can pass through the cell membrane via endocytosis, but, if they are left as they are, decompose resulting in a low expression efficiency. Thus, as a measure to improve the escape from transport vesicles, studies have been conducted on the utilization of pH-sensitive membrane-fusing substances, with recognized effectiveness.    Non-patent reference 7: Cho, Y. W., Kim, J. D., and Park, K. (2003) J. Pharm Pharmacol., 55 (6), 721-34.
The nuclear import of exogenous genes can be counted as one of the biggest barriers to the improvement of transfection efficiency in the use of non-viral vectors. As an approach for overcoming this issue, extensive studies have been made on the utilization of the nuclear import system of nuclear proteins in eukaryotic cells.
Nuclear proteins are generally tagged with a nuclear localization signal (NLS), to which is bound importin-α, a mediator for the material to be imported. There is finally formed a complex in which importin-β is bound to the importing material, for energy-dependent and selective import of nucleic acid through the nuclear pores present in the nuclear envelope.    Non-patent reference 9: Pexach, M., and Blobel, G., Cell 83, 683-692, (1995).    Non-patent reference 10: Yoneda, Y., J. Biochem, Tokyo 121, 811-817 (1996).
Thus, a number of studies have been made on the promotion of nuclear import and, by extension, the enhancement of expression efficiency, by complexing exogenous gene with a NLS peptide. However, the methodology has not yet been established since advantageous effects are ascertained in some cases, whereas there are some reports negating significant effects on expression efficiency. This may be partly because the formation of the complex proceeds in two-staged reactions resulting in a decreased efficiency.    Non-patent reference 11: Zanta, M. A., Belguise-Valladier, P., and Behr, J. P., Proc. Natl. Acad. Sci. U.S.A. 96 91-96 (1999).    Non-patent reference 12: Collas, P., and Alestrom, P., Biochem. Cell. Biol., 75, 6333-640(1997).    Patent reference 1: Japanese Patent Application Publication No. 1999-506935.    Patent reference 2: Japanese Patent Application Publication No. 2002-514892.    Patent reference 3: Japanese Patent Application Publication No. 2002-533088.    Non-patent reference 13: Nagasaki, T., Myohoji, T., Tachibana, T., and Tamagaki., S., Bioconjugate Chem., 14, 282-286 (2003).    Non-patent reference 14: Tanimoto, M., Kamiya, H., Minakawa, N., Matsuda, A and Harashuma, H., Bioconjugate Chem., 14, 1197-1202 (2003).
It is further to be noted that the expression efficiency is lowered when the exogenous gene is imported into the nucleus as it is bound with the carrier compound which functions as a non-viral vector. Therefore studies have been made on stimuli-responsive carriers, such as photo-responsive or redox-responsive carriers, for the enhancement of DNA release in the nucleus.    Non-patent reference 15: Miyata, K., Kakizawa, Y., Nishiyama, N., Harada, A., Yamazaki, Y., Koyama, H., Kataoka, K (2004) J Am Chem Soc., 126 (8), 2355-61.
Thus, although means have been proposed, on a piecemeal basis, for overcoming the barriers to non-viral vectors in the transport process of a nucleic acid from outside of a cell into the cell nucleus, there are found no organized systems providing collective advantageous effects by the non-viral vectors with a satisfactory efficiency.

Nuclear transport nucleic acid delivery vector


The present invention is directed to a system and method that includes a vehicle that exchanges information with the remote location by way of a communication network. A remote server transmits vehicle-related information to the vehicle by way of a communication system. Information may also be broadcast to and received by the vehicle by way of a broadcast communication system. A receiver of the vehicle provides user access to only a subset of the broadcast information based on user preferences of a user profile. The user may update the user profile by accessing and updating it at either the vehicle or by accessing a database. The user may access the database through a network, such as the Internet. The vehicle also selectively transmits vehicle-related information to the remote location when a predetermined event occurs. The vehicle-related information is compiled and analyzed at the remote location, and the analyzed information is transmitted back to the vehicle.

1. Field of the Invention
The present invention relates to a method and system for providing information to vehicles from a remote location and for providing vehicle related information from a vehicle to the remote location.
2. Description of Related Art
The upkeep and maintenance of vehicles is essential to maintain a vehicle in good running condition and to maintain the overall reputation of a vehicle manufacturer. For example, even if a vehicle malfunctions or breaks down because of user neglect, as opposed to a vehicle defect, the reputation of the vehicle manufacturer will still be injured, especially if several vehicles malfunction because of user neglect. Thus, as users often neglect to regularly service their vehicles, upgrade their vehicles with improved replacement parts, and in some cases, even forget to replace recalled vehicle parts—it is important to remind users to service their vehicles.
Known methods to remind users are very inflexible, cumbersome and inefficient. In previous methods, vehicles were manufactured with warning lights that are activated when an event occurs. For example, maintenance reminder lights and low oil level lights are activated to remind users to bring their car to a service provider. The lights are activated only according to the time intervals and levels that were originally preprogrammed into a memory of the vehicle. Thus, if a service provider that a user often went to service his vehicle determined that a new service schedule should be used that differed from the original preprogrammed schedule, he could not update the memory to incorporate the new schedule or it would be very difficult to do so. Likewise, if a user wanted to deactivate such reminders, the user could not do so without following an intricate set of steps, which usually required the assistance of a professional service provider to carry out.
Moreover, subsequent developments, such as car part recall notices or the development of an improved part to be used in the vehicle, could not be sent to the vehicle by using such previous methods. To inform users of such developments, vehicle manufacturers and other service providers were forced to resort to mailing product brochures and the like to users. The process of mailing brochures is not only expensive, but timely, cumbersome and inefficient.
Even if a user wished to bring in his car for service in response to a warning light or receiving an updated brochure, the user would be required to locate the phone number of the service provider, contact the service provider and schedule an appointment. The user would be forced to schedule the appointment after he exited the vehicle because much of the information a user would need to make the appointment is typically not carried with the user. After exiting the vehicle, the user may forget to schedule the appointment, despite the maintenance notification lights.
Other known methods provide retail and sales information to a vehicle based on a profile of the user, but such methods do not provide vehicle-related information to a user. As a result, the other methods do not address the need to provide a convenient and flexible way to inform the user of service schedules, product recalls and other notices pertinent to the vehicle.
In addition, in known methods, users oftentimes observe the preprogrammed notices but do not comprehend the significance of the notices. In other words, users oftentimes do not understand whether they should bring the vehicle for service in response to the notice or when they should bring their vehicle in. Previous methods provided a two-way calling mechanism for the user to place a call to a live operator when the notice appears. The live operator can then explain the significance of the notice to the user. Other methods automatically send a message to the live operator when an air bag of the vehicle deploys.
Such known methods, however, are very limited and inflexible. For example, users do not have the option to determine whether information regarding the occurrence of an event should be transmitted automatically, not transmitted or transmitted on a case-by-case basis to a remote location. In the prior art methods, users do not have the option to automatically send information about the occurrence of most events to the remote location. Rather, the users must manually use the two-way calling mechanism to inform an operator that a notification light has been activated. As a result, the previous methods leave the user with limited and inflexible ways to transmit information pertaining to vehicle problems to a remote location.
Other known methods have attempted to send general information to particular vehicles, but have used very inefficient and inflexible ways to do so. For example, the known methods use one-to-one communication systems to individually send data streams to particular vehicles in an attempt to send vehicle specific data to a particular vehicle. The problem with these methods, however, is that many vehicles require the same information. For example, several vehicles might require world or national news information. The previous methods, therefore, require the transmittal of the same information several times to a plurality of vehicles, which results in a wastage of precious bandwidth.
Other methods involve the transmittal of the same information to all vehicles. The problem with these methods, however, is that many vehicles are inundated with a large amount of unwanted information and the users are required to sift through the unwanted information.
As a result, there remains a need for methods that allow for the transmittal of vehicle-related information from a remote location to a vehicle and that allow for the selective transmittal of vehicle related information from a vehicle to a remote location. There also remains a need for an efficient method for sending vehicle specific information to vehicles.

Method and system for facilitating the exchange of information between a vehicle and a remote location


A table searching system for facilitating high speed linear searching of a table of information by a plurality of searching agents is provided. The system includes: a memory unit for storing a table of information including a plurality of data entries each having data contents; a plurality of searching agents each being communicatively coupled with the memory unit, and having a port for receiving an associated search key value; and a memory controller unit providing a centralized interface between the memory unit and each of the agents, the controller unit being operative to control the memory unit to provide the contents of a current one of the table entries to each of the agents during each of a plurality of cycles of operation. Each of the searching agents is operative to determine an associated best matching one of the data entries based on comparisons between the associated key value and the contents of the data entries provided by the memory unit.

1. Field of the Invention
The present invention relates generally to a method and apparatus for searching an electronically stored table of information including a plurality of table entries, and more specifically to a method and apparatus for facilitating high speed linear searching of a table by a plurality of agents that are each required to search many entries of the table using different search keys.
2. Description of the Related Art
In the fields of electronic data communications and data processing, electronically stored tables of information are used in vast variety of applications to provide a mapping between two or more information spaces. The tables of information, which include a plurality of entries, may be searched in accordance with many different methods.
Generally, a searching agent searches a table using a search key, and may read one or more tables entries to determine an exact match or a best match depending on the particular application requirements. It is a common design requirement that each of a plurality of searching agents having different search keys is required to search a single table of information. For applications in which it is generally not feasible to employ a multiplicity of memory devices storing the same table of information, an arbitration scheme is typically employed to resolve requests from each of the searching agents for access to the single table.
Many algorithms and devices have been developed to efficiently search tables of information. A basic brute force method is linear searching wherein a device searches a table linearly one entry at a time. Linear searching is the simplest search method, and it is ideal for searching small tables in applications having slow search requirements. However, linear searching becomes impractical as the table sizes increase because the maximum search time is proportional to the table size.
In order to shorten the table search time, binary searching methods may be used wherein all entries of the table are sorted in a particular order, and the search times are equal to log2 (table size). Binary searching methods are particularly desirable for searching large tables using software, but sorting the table entries in a particular order is not a simple task. Due to this high maintenance requirement, binary searching is often not feasible to implement in hardware.
One of the quickest methods of table searching uses content addressable memory (CAM) searching wherein all table entries are compared against a search key at the same time, and the search result is delivered to an output instantly. However, CAM searching provides high search performance at the expense of implementing greater logic using a greater amount of silicon real estate. Moreover, there is typically a limit to the size of comparison fields (i.e. data width) and the size of payload fields which may be used in CAM searching.
Some of the most common methods of table search employ hashing algorithms in which table entries are grouped into different buckets in accordance with the particular type of hashing algorithm (i.e. crc32). Searching systems employing hashing algorithms are capable of narrowing the searching area to a specific location (a bucket), and this limits the maximum searching time. The maximum table searching time is based on the size of the bucket, and the table search time remains constant as the number of buckets increases. As the number of the table entries increase, the possibility that two or more entries are hashed to a same bucket also increases. If the maximum table entry (the size of table) is considerably larger than the typical number of entries used at the same time and the hash algorithm spreads the entries evenly, there is a good chance that only one or two entries are in a bucket. In this case, the average search time will be rather short (one or two clock cycles per search). A good hash algorithm scatters table entries evenly over the search table, but there is a possibility that many table entries may hashed into the same bucket. Thus, using 100 percent of a table is not practical, and the size of the table often needs to be much larger than the typical number of table entries.
In the field of data communications, there are many applications wherein each of a plurality of searching agents is required to search a single table of information. In routing and switching devices, a table of information is often used to provide a mapping mechanism for forwarding data, typically in the form of a packet (e.g., an Ethernet Packet), from one location to another location.
As packets arrive at each of a plurality of associated ports of a switch or router device, a plurality of port searching agents, each associated with one of the ports, must search information stored in the table to determine an appropriate action. For example, if the table includes an entry providing a direction for the arrived packet, the device forwards the packet in the direction indicated. If the table does not include an entry providing a direction for the arrived packet, the device may handle the packet based on a default setting. Examples of default settings include sending the packet to all available ports (broadcasting), sending the packet to a central processing unit (CPU) for analysis in accordance with a predefined set of rules, or dropping the packet. For Ethernet routing applications, a table of information is typically organized based on particular fields (e.g., a medium access control (MAC) Address, an IP Address, a Virtual LAN ID, etc.) of a packet. When particular fields of the packet match particular fields of the table, the device utilizes the corresponding information in the table to forward the packet.
In conventional table searching systems wherein each of a plurality searching agents is required to search a single table of information, a "pull" searching method is typically employed wherein each of the searching agents is required to initiate table searching. An arbitration scheme is usually employed to resolve requests initiated by each of a plurality of searching agents for access to the single table.
FIG. 1 shows a generalized block diagram of a conventional table information searching system at 10, the system operating in accordance with conventional pull search techniques. The system 10 includes a plurality of N+1 searching agents 12 designated AGENT_0, AGENT_1, . . . AGENT_N. As an example, each of the searching agents 12 may be a port agent communicatively coupled with a receiving port of a switching device. Each of the searching agents 12 includes: a receiver port 14 for receiving a search key (e.g., a destination address of a data jacket); an arbitration request signal output port 16 for providing one of a plurality of N+1 request signals designated REQ_0, REQ_1, . . . REQ_N; an arbitration grant signal input port 18 for receiving an associated one of a plurality of N+1 grant signals designated GNT_0, GNT_1, . . . GNT_N; a table data input port 20 for receiving table information via a table data bus 21 as further explained below; and a memory address output port 22 for providing address values to a search address bus 23 as further explained below.
The system 10 further includes; an arbitration logic unit 26 having a plurality of request signal input ports 28 for receiving associated ones of the arbitration request signals, and a plurality of N+1 arbitration grant signal output ports 30 each providing an associated one of the arbitration grant signals to port 18 of an associated one of the agents 12; and a table information memory unit 36 for storing a table of information, and having a table data output port 38 for providing table data to the table data input port 20 of selected ones of the searching agents 12 via the bus 21, and a search address input port 40 for receiving the memory address values from the ports 22 of selected ones of the agents 12.
The table information memory unit 36 is typically implemented using static random access memory (SRAM) technology, and therefore only one of the entries of the table of information stored therein may be accessed at a time. Because of this fundamental feature of SRAM technology, only one of the agents 12 may access the table information unit 36 at a time. However, each of the agents 12 may have a different search key value for searching the table stored in the memory unit 36, and therefore there is a conflict.
Because only one of the table entries stored in the memory unit 36 may be accessed at a time, the arbitration logic unit 26 is needed to arbitrate among requests received from the searching agents 12 for access to the memory unit. The arbitration logic unit 26 receives and resolves the requests, and provides the grant to select corresponding ones of the searching agents 12. In response to the associated one of the grant signals being asserted, a selected searching agents 12 begins to provide one or more address values sequentially to port 40 of the memory unit 36 via the bus 23. In response to each of the address values, the memory unit provides the contents of a table entry stored at the specified address, to all the agents via the data bus, although only selected agents process the data from the memory. Each of the agents is operative to execute a searching process to determine a match between the search key value and one of the table entries. If the searching system needs to search every table entry to determine a best available match, instead of an exact match, the required search time becomes very lengthy.
A problem associated with the prior art table searching system 10 is that the system is not scalable to a large number of searching agents 12 because only one of the agents 12 may access the table information unit 36 at a given time, and so the total required search time for processing all the search key increases linearly as the number of searching agents increases because only one search key can be processed at a time in accordance with "pull" search techniques. Stated alternatively, the total number of cycles required for searching is proportional to the number of searching agents.
For example, in a switching device, as the number of port searching agents (each having a different destination address of an associated incoming packet) increases linearly, the required search time increases linearly because only one packet can be processed at a time in accordance with "pull" search techniques. This becomes a major performance bottleneck when the switching device requires the processing of a large number of packets simultaneously. For example, if the minimum packet forwarding time is 80 clock cycles and the maxim search time is eight clock cycles, the switching device can forward a maximum of ten packets at the same time. If the switching device needs to forward more than ten packets at the same time, then search table using a "pull" search technique becomes a performance bottleneck. This is especially crucial if the maximum search time is very large. If the searching system needs to search every table entry to determine a best available match, instead of an exact match, the search time for processing multiple packets is quite lengthy.

Method and apparatus for high speed table search


An impulse response between a sound-producing source and a listening point in an acoustic space is measured. A frequency characteristic serving as the processing target of sound field correction is derived from the impulse response. A level difference at a boundary frequency between a level representing a low frequency band and a level representing middle and high frequency bands is calculated for the low frequency band equal to or lower than the boundary frequency and the middle and high frequency bands higher than the boundary frequency in the frequency characteristic. The level of a target characteristic in the low frequency band in the frequency characteristic is decided to set the level difference after sound field correction to be equal to or smaller than a predetermined value.

Field of the Invention
The present invention relates to a sound field correction technique of correcting the influence of the interference between a plurality of sound waves on the frequency characteristic in an acoustic space so as to obtain a target characteristic.
Description of the Related Art
When a sound is produced from a sound-producing source such as a speaker in a space having wall surfaces such as a wall, floor, and ceiling in a room of a house, sounds reflected by the respective surfaces of the room in addition to the direct sound reach a sound capture point in the space, and a plurality of sound waves interfere with each other. In general, the resonance phenomenon in the room mode (natural vibration mode having features such as the transmission characteristic of a room depending on the dimensions of the room) occurs at frequencies corresponding to the dimensions of the room. This phenomenon is called a standing wave. Even when no wall surface exists in a space, if a plurality of sound-producing sources are used, direct sounds may interfere with each other.
In this manner, when a plurality of sound waves interfere with each other, the interference greatly influences the frequency characteristic at a sound capture point. More specifically, when a microphone is located at the sound capture point and a measurement signal is produced from the sound-producing source to measure an impulse response between the sound-producing source and the sound capture point, peaks and dips are generated on the graph of the amplitude-frequency characteristic (dB expression of this characteristic will be called an "f characteristic" hereinafter). Especially in a low frequency band in which the influence of the room mode prevails, large peaks and dips appear on the f characteristic.
In this case, when the sound-producing source is a speaker, the sound capture point is a listening point, and the user listens to music in the room, the sound quality in audibility is greatly degraded such that the volume of a sound of a peak frequency excessively increases and causes booming, whereas a sound is omitted at a dip frequency. Therefore, a sound field correction technique of applying a filter to a reproduce signal to cancel large peaks and dips on the f characteristic of the impulse response and improve the sound quality becomes important.
FIG. 5A shows the f characteristics of a total of nine impulse responses corresponding to three sound-producing patterns (only L, only R, and L+R) between stereo speakers and three points in a listening area including a listening point in given room A. In FIG. 5A, the boundary between the low frequency band and the middle and high frequency bands is set to be 200 Hz. Especially in the low frequency band, the influence of the room mode prevails, and steep peaks and dips are generated on each f characteristic.
It is generally known that the shape of the f characteristic and the human audibility do not always coincide with each other in the low frequency band, but they match well in the middle and high frequency bands. For this reason, sound field correction is not always necessary for the middle and high frequency bands, and there is a choice of not performing correction is possible. However, sound field correction is basically necessary for the low frequency band in order to cancel steep peaks and dips. In Japanese Patent No. 3556427, when sound field correction is performed using an adaptive filter, the calculation amount is reduced by performing correction in only the low frequency band in which the f characteristic or group delay characteristic of the impulse response is disturbed.
FIG. 6 is a graph showing an example of the design of a sound field correction filter for the low frequency band of the f characteristic in FIG. 5A. An average f characteristic 601 before correction indicated by a thick dotted line is an f characteristic obtained by averaging the low frequency band portions, each as the target frequency band of sound field correction, of the nine f characteristics in FIG. 5A. The average level of the average f characteristic 601 before correction is set as a correction target level 602 indicated by a horizontal line in FIG. 6. The sound field correction filter is designed to suppress, toward the correction target level 602, steep peaks and dips on the average f characteristic 601 before correction.
For example, a biquadratic IIR (Infinite Impulse Response) peak filter capable of implementing a steep filter characteristic by a small processing amount is suitable as a filter for canceling steep peaks and dips. Peak filters that set negative and positive filter gains are assigned to respective peaks and dips on the average f characteristic 601 before correction. These peak filters are series-connected into an overall sound field correction filter. The thus-designed sound field correction filter has a correction filter f characteristic 603 indicated by a thick solid line. The correction filter f characteristic 603 is applied to the average f characteristic 601 before correction, obtaining an average f characteristic 604 after correction similarly indicated by a thick solid line. This sound field correction filter is designed not to completely raise a dip or completely lower a peak to the correction target level 602, in order to avoid excessive correction. Hence, the average f characteristic 604 after correction has a gradual undulation near the correction target level 602, but steep peaks and dips that cause a problem in audibility are canceled.
Each f characteristic in FIG. 5B is obtained by applying the correction filter f characteristic 603 to each f characteristic in FIG. 5A, and steep peaks and dips are suppressed, as in the average f characteristic 604 after correction in FIG. 6. When attention is paid to the balance of the whole f characteristic including not only the low frequency band but also the middle and high frequency bands, each f characteristic in FIG. 5B has good balance between the low frequency band and the middle and high frequency bands. More specifically, the average level of the respective f characteristics in the low frequency band is drawn as a horizontal line in the low frequency band of FIG. 5B, and the approximate straight lines (approximate characteristics) of the respective f characteristics in the middle and high frequency bands are drawn as downward sloping lines in the middle and high frequency bands. Then, at the 200-Hz boundary between the low frequency band and the middle and high frequency bands, the horizontal line of the average level of the respective f characteristics in the low frequency band and the approximate straight lines in the middle and high frequency bands are smoothly connected without a large level difference, as indicated by a circled portion. When an audition experiment was conducted in a state in which the low frequency band and middle and high frequency bands of each f characteristic were balanced, as shown in FIG. 5B, a good audibility result was obtained.
In contrast, FIG. 3A shows a total of nine impulse response f characteristics at three points in a listening area, as in room A, as for another room B different from the room for FIG. 5A. In the low frequency band of 200 Hz or lower, the influence of the room mode is weaker than that in room A, and peaks and dips on each f characteristic are not so larger than those in FIG. 5A. However, when attention is paid to the balance between the low frequency band and the middle and high frequency bands, a steep step is generated between the low frequency band and the middle and high frequency bands, as indicated by a circled portion in FIG. 3A, unlike room A. The level in the low frequency band is much higher than that in the middle and high frequency bands.
FIG. 4A shows an example of the design of a sound field correction filter for the low frequency band of the f characteristic in FIG. 3A by the same method as that described with reference to FIG. 6. A correction filter f characteristic 403 of the designed sound field correction filter is applied to an average f characteristic 401 before correction, obtaining an average f characteristic 404 after correction. The correction filter f characteristic 403 is applied to each f characteristic in FIG. 3A, obtaining each f characteristic in FIG. 3B. This f characteristic reveals that peaks and dips in the low frequency band are suppressed. However, in terms of the balance between the low frequency band and the middle and high frequency bands, the steep step between the low frequency band and the middle and high frequency bands shown in FIG. 3A still remains even in FIG. 3B after sound field correction.
When an audition experiment was conducted in a state in which the level of each f characteristic in the low frequency band was much higher than that in the middle and high frequency bands owing to a step as in FIG. 3B, the user excessively felt the low frequency band, and the audibility was greatly impaired. It is considered that even when peaks and dips in the low frequency band, which may generate a problem in audibility in general, are canceled, if the balance between the low frequency band and the middle and high frequency bands is poor, the audibility is impaired.
The method in Japanese Patent No. 3556427 cancels the disturbances of the f characteristic and group delay characteristic in the low frequency band, but does not consider the balance between the low frequency band and the middle and high frequency bands. Further, the following problem arises even in a method of introducing a filter other than the sound field correction filter in order to cancel a steep step between the low frequency band and the middle and high frequency bands, as in room B.
Ideally, a filter for canceling a steep step and adjusting the level in the low frequency band to the level in the middle and high frequency bands has a gain of 0 dB for the middle and high frequency bands and a negative gain corresponding to the step size for the low frequency band, and has a characteristic in which the gain abruptly changes at the boundary between the low frequency band and the middle and high frequency bands.
However, a great many taps are necessary to implement, by an FIR (Finite Impulse Response), a filter having a steep characteristic at a relatively low frequency. Owing to the convolution processing amount, other acoustic processes such as tone control, loudness equalization, and a compressor are hindered. If the number of taps is decreased, the characteristic becomes moderate at a portion where a steep characteristic is required, and a new peak or dip is generated at the boundary between the low frequency band and the middle and high frequency bands. For example, even when a low-shelf IIR is used, if a steep characteristic is implemented at a low frequency, the filter characteristic is disturbed at the boundary between the low frequency band and the middle and high frequency bands.
When the speaker is a multi-way speaker having a plurality of diaphragms for respective bands, the balance between the low frequency band and the middle and high frequency bands may be adjusted by adjusting the gain of a woofer in charge of the low frequency band. However, the crossover frequencies of the woofer and a squawker in charge of the middle and high frequency bands hardly coincide with the frequency of a steep step to be canceled. Even if these frequencies coincide with each other, crossover filters for band division have been applied to the woofer and the squawker. For this reason, the synthesis of the woofer and squawker after gain adjustment becomes the synthesis problem of the crossover filter having a step. A steep step corresponding to the gain adjustment amount cannot be simply implemented at the crossover frequency, and new peaks and dips are generated after all.
In this manner, when a steep step remains in the f characteristic after sound field correction, it is difficult to clearly cancel the steep step by another filter or the like. Considering that a peak filter also having a steep characteristic is used to cancel steep peaks and dips on the f characteristic in the low frequency band in sound field correction, this peak filter may also be used to cancel a steep step between the low frequency band and the middle and high frequency bands.

Sound field correction apparatus, control method thereof, and computer-readable storage medium


A digital tachograph has a security module. A public key, a secure private key, and a signage are stored in the security module. Vehicle-relevant data and the corresponding checksum are encoded using a secure private key and stored in the digital tachograph in a data format by the security module.

1. Field of the Invention
The invention relates to a digital tachograph and to a method for signing vehicle-relevant data.
2. Related Art
DE 197 38 631 A1 discloses a method and an arrangement for monitoring motor vehicles, wherein the motor vehicles contain a tachograph for ascertaining and storing a piece of journey-specific information and the stored pieces of information are checked, with the piece of information from an electronic tachograph being transmitted to a remote query module in the motor vehicle, the piece of information being transmitted to an external query appliance and the piece of information being conditioned and presented in the query appliance. The remote query module is intended to send only following a correct request by a query appliance.
A method and an appliance for documenting vehicle data are disclosed by DE 197 10 333 A1. This document proposes the vehicle data is collected by a data memory unit installed in the vehicle, conditioned and stored in a storage medium up until external processing. It is intended to be possible to store data on a chip card in encrypted form and to decrypt the data using an evaluation program.
DE 100 32 301 A1 discloses a travel data acquisition, travel data transmission and travel data output system for use in a public local or long-distance transport network with a travel data generator, a travel data transmitter and a travel data receiver. The travel data generator is intended to automatically capture and encode data from a respective vehicle, and the travel data transmitter is intended to transmit the travel data captured and encoded by the travel data generator.
According to European community regulations 2135/98, 1360/2002 and 3821/85, a digital tachograph needs to be shown for all commercial vehicles with a vehicle weight greater than 3.5 t and for certain buses on the registration date within EU member states from May 1, 2006 onward. The aim of digital tachographs is to combat simple opportunities for misuse in order to be able to undertake protected and confidential storage of these travel data on a personal driver card and in a mass memory in the appliance through the use of digital data processing. If necessary, the travel data can be printed. Digital tachographs need to be checked for functionality, and calibrated, at least every two years.
At present, it is possible for vehicle-relevant data that are recorded and ascertained by a digital tachograph, such as driving-period, to be manipulated, the manipulation not being evident to outside third parties, such as regulatory authorities. For the regulatory authorities, such as the police, this means that the vehicle-relevant data to be checked for a vehicle that is to be checked are unreliable, since it is not possible to check whether they are authentic and/or have not been manipulated.
The recorded vehicle-relevant data might have been changed, with it not being clearly evident what prompted the change, since it is not possible to distinguish whether mischievous manipulation, or incorrect information produced by transmission errors is involved. As a result, trustworthiness for rating the vehicle-relevant data can be classified as low. Current "trust-based" solutions for the capture of vehicle-relevant data can be regarded as suspect for a check by the regulatory authorities. The existing legal regulations that identify the data attributes of the vehicle-relevant data that need to be captured and must not be changed provide no guidelines with regard to reliability against manipulation and hence no Q factor or quality indicator about the reliability of the data attributes of the vehicle-relevant data per se that need to be captured. Therein lies the opportunity to make unrecognizable modifications to the vehicle-relevant data. In the existing legal guidelines, the captured vehicle-relevant data are totally unprotected and can be regarded as not forgery-proof.


A method and system for defining and generating forecasts. The forecast system receives a forecast definition from a user, generates a forecast in accordance with the forecast definition, stores a forecast snapshot of the generated forecast, and presents to users forecast information derived from the forecast snapshots. A forecast definition specifies the participants to be included in a forecast and when to generate the forecast. At the scheduled time, the forecast system automatically generates the forecast and stores the forecast snapshot.

Many organizations need to track the business opportunities of their sales forces. By tracking various business opportunities, an organization can forecast business statistics such as revenue and product quantities based on those opportunities. In addition, organizations generally would like to monitor how their actual revenue relates to their forecasted revenue based on actual-to-forecasted business statistics. By monitoring actual revenue, an organization can determine whether it is on track to meet its forecasted revenue. If it is not on track, then the organization can take appropriate actions.
Traditionally, each salesperson in an organization would track their own opportunities and, when requested, would provide their forecasts to their sales manager. Upon receiving these forecasts, a sales manager might create a spreadsheet that totals the forecasts of all the sales people reporting to that sales manager. That sales manager would then provide a summary of the forecast to a regional or divisional sales manager. Unfortunately, because only summary forecast information is provided to the next management level within a sales force, a certain manager may not have access to the historical details used to generate such forecasts. As a result, a manager may not be able to easily identify revenue or forecasting problems.
Some enterprise-based solutions have been developed that allow organizations to track their forecasts and the supporting details. These enterprise-based solutions assume a highly experienced administrator will set up and manage the forecasts for each organization. For example, some enterprise-based solutions allow an administrator to define the SQL queries that specify how forecasts are to be generated. However, it takes a high degree of sophistication to correctly define SQL queries. In addition, these enterprise-based solutions typically display forecast information on a record-by-record basis that may not provide an effective overview of the forecast information. Also, these enterprise-based solutions require that an administrator manually initiate each forecast, which can present problems if the administrator is unavailable or forgets to initiate a forecast at the appropriate time.
It would be desirable to have a forecast system that can be used by less experienced users and would provide forecast information in a way that can be used more effectively by less experienced users.

Method and system for automatically generating forecasts


The disclosure, in one aspect, relates to methods of preparing a CHA zeolite under ambient pressure conditions. In further aspects, the disclosure relates to methods such that a mother liquor can be isolated from a disclosed method, and recycled for use in a disclosed method for further preparation of a CHA zeolite. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.

Zeolites are crystalline or quasi-crystalline aluminosilicates constructed of repeating SiO, and AlO4 tetrahedral units. These units are linked together to form frameworks having regular intra-crystalline cavities and channels of molecular dimensions. Numerous types of synthetic Zeolites have been synthesized and each has a unique framework based on the specific arrangement its tetrahedral units. By convention, each framework type is assigned a unique three letter code (e.g., "CHA") by the International Zeolite Association (IZA). Chabazite (CHA) is a molecular sieve framework that is highlighted for the eight-membered ring (8-MR) structural feature.
The industrial importance of CHA has been well described by Bull, et al. in US Patent Appl. No. 2009/0285737 described using the SSZ-13 CHA (Zones synthesis) in as a selective catalytic reduction (SCR) catalyst. SCR technology is widely used in the emission control industry to reduce NOx emissions. Ji described a process to perform post synthesis steaming of aluminum silicate CHA to achieve a methanol to olefins (MTO) catalysts. MTO can potentially be an important process for the overall refinement of natural gas (methane converts to methanol).
The synthesis of the aluminum silicate version of CHA with only sodium as an alkali in the reactive medium and the use of a structure directing agent (SDA) have been extensively studied. This process was originally described by Zones, et al. in U.S. Pat. No. 4,544,538. Faujasite (FAU) conversion has been a well-established technique for synthesizing smaller pore zeolites such as an 8-MR CHA. The original example of a FAU conversion to obtain CHA was described in U.S. Pat. No. 4,503,024. This FAU conversion technique was able to push the activation energy for CHA synthesis down far enough to possibly have an ambient pressure. The synthesis described by Bourgogne describes a process that involved a potassium containing synthesis media without the use of an SDA. The CHA produced under potassium containing conditions will have potassium ions in the product. This product causes an issue with removing the large potassium ions from the structure in post synthesis procedures. The use of a potassium containing CHA in a catalytic system as compared to a sodium containing CHA will produced a diminished catalytic performance because of the large ion removal affect. With the Bourgogne synthesis, the large potassium can be thought of as an SDA. Use of an SDA is also a variable that drives down the activation energy in the synthesis. Other methods to drive down the activation energy of zeolite synthesis has been described Cecil, et al. in U.S. Pat. No. 4,576,807. The FAU synthesis described by Cecil was accelerated by having a low water proportion of the synthesis media and using seeds.
For purposes of driving down the activation energy and having a sodium reaction media (avoiding potassium) in an ambient pressure reactor, a carefully thought out procedure involving parts of the previously described techniques can achieve this goal. A sealed reflux reactor system is still required for this invention to maintain water balance. An ambient pressure reactor compared to a high-pressure reactor is a much more efficient vessel for synthesis. Eliminating the need to pressurize the synthesis vessel greatly reduces the process requirements to perform synthesis. Additionally, the capital expenditure related to an ambient pressure process is far less than a high-pressure process. The requirement of heavy duty parts and added safety devices are a considerable expense for pressure reactors. For added benefit of reducing overall input and effluent of the process, mother liquor (ML) recycle is an important step. Solid product is removed and the mother liquor is reused as a reagent in a subsequent batch. Vaughan used ML recycle for a FAU zeolite synthesis described by Vaughan, et al. in U.S. Pat. No. 5,637,287.
Despite advances in research directed to preparation of zeolite materials, there is still a scarcity of methods that permit preparation of CHA zeolite under conditions of ambient pressure. These needs and other needs are satisfied by the present disclosure.

Methods for preparation of CHA Zeolite at ambient pressure