A soft-computing method for establishing the dissipation law of the heat in a diesel Common Rail engine, in particular for establishing the dissipation mean speed (HRR) of the heat, includes the following steps:                choosing a number of Wiebe functions whereon a dissipation speed signal (HRR) of the heat is decomposed;        applying a Transform Ψ to the dissipation speed signal (HRR) of the heat;        carrying out analysis of homogeneity of the Transform Ψ output;        realizing a corresponding neural network MLP wherein the design is guided by an evolutive algorithm; and        training and testing the neural network MLP.

For several years, the guide line relating to the fuel-injection control in a Diesel Rail engine has been the realization of a micro-controller able to find on-line, i.e., in real time while the engine is in use, through an optimization process aimed at cutting down the fuel consumption and the polluting emissions, the best injection strategy associated with the load demand of the injection-driving drivers.
Map control systems are known for associating a fuel-injection strategy with the load demand of a driver which represents the best compromise between the following contrasting aims: maximization of the torque, minimization of the fuel consumption, reduction of the noise, and cut down of the NOx and of the carbonaceous particulate.
The characteristic of this control is that of associating a set of parameters (param1, . . . , paramn) to the driver demand which describe the best fuel-injection strategy according to the rotational speed of the driving shaft and of other components.
The analytical expression of this function is:(param1, . . . , paramn)=f(speed, driver demand)  (1)
The domain of the function in (1) is the size space ∞2 since the rotational speed and the driver demand can each take an infinite number of values. The quantization of the speed and driverDemand variables (M possible values for speed and P for driverDemand) allows one to transform the function in (1) (param1, . . . , paramn) into a set of n matrixes, called control maps.
Each matrix chooses, according to the driver demand (driverDemandp) and to the current speed value (speedm), one of the parameters of the corresponding optimal injection strategy (parami):{tilde over (f)}(i)m,p={tilde over (f)}(i)(speedm, driverp)=parami  (2)where i=1, . . . , n, m=1, . . . , M e p=1, . . . , P
The procedure for constructing the control maps initially consists of establishing map sizes, i.e., the number of rows and columns of the matrixes.
Subsequently, for each load level and for each speed value, the optimal injection strategy is determined, on the basis of experimental tests.
The above-described heuristic procedure has been applied to a specific test case: control of the Common Rail supply system with two fuel-injection strategies in a diesel engine, the characteristics of which are reported in FIG. 1. FIG. 2 shows a simple map-injection control scheme relating to the engine at issue. In the above-described injection control scheme, the real-time choice of the injection strategy occurs through a linear interpolation among the parameter values (param1, . . . , paramn) contained in the maps.
The map-injection control is a static, open control system. The system is static since the control maps are determined off-line through a non sophisticated processing of the data gathered during the experimental tests; the control maps do not provide an on-line update of the contained values.
The system, moreover, is open since the injection law, obtained by the interpolation of the matrix values among which the driver demand shows up, is not monitored, i.e., it is not verified that the NOx and carbonaceous particulate emissions, corresponding to the current injection law, do not exceed the predetermined safety levels, and whether or not the corresponding torque is close to the driver demand. The explanatory example of FIG. 3 represents a typical static and open map injection control.
A dynamic, closed map control is obtained by adding to the static, open system: a model providing some operation parameters of the engine when the considered injection strategy varies, a threshold set relative to the operation parameters, and finally a set of rules (possibly fuzzy rules) for updating the current injection law and/or the values contained in the control maps of the system.
FIG. 4 describes the block scheme of a traditional dynamic, closed, map control.
It is to be noted that a model of the combustion process in a Diesel engine often requires a simulation meeting a series of complex processes: the air motion in the cylinder, the atomization and vaporization of the fuel, the mixture of the two fluids (air and fuel), and the reaction kinetics, which regulate the premixed and diffusive steps of the combustion.
There are two classes of models: multidimensional models and thermodynamic models. The multidimensional models try to provide all the fluid dynamic details of the phenomena intervening in the cylinder of a Diesel, such as: motion equations of the air inside the cylinder, the evolution of the fuel and the interaction thereof with the air, the evaporation of the liquid particles, and the development of the chemical reactions responsible for the pollutants formation.
These models are based on the solution of fundamental equations of preservation of the energy with finite different schemes. Even if the computational power demanded by these models can be provided by today's calculators, we are still far from being able to implement these models on a micro-controller for an on-line optimization of the injection strategy of engine.
The thermodynamic models make use of the first principle of thermodynamics and of correlations of the empirical type for a physical but synthetic description of different processes implied in the combustion; for this reason these models are also called phenomenological. In a simpler approach, the fluid can be considered of spatially uniform composition, temperature and pressure, i.e. variable only with time (i.e. functions only of the crank angle). In this case, the model is referred to as "single area" model, whereas the "multi-area" ones take into account the space uneveness typical of the combustion of a Diesel engine.
In the case of a Diesel engine, as in general for internal combustion engines, the simplest way to simulate the combustion process is determining the law with which the burnt fuel fraction (Xb) varies.
The starting base for modelling the combustion process in an engine is the first principle of the thermodynamics applied to the gaseous system contained in the combustion chamber. In a first approximation, even if the combustion process is going on, the operation fluid can be considered homogeneous in composition, temperature and pressure, suitably choosing the relevant mean values of these values.
Neglecting the combustible mass that Q flows through the border surface of the chamber, the heat flow dissipated by the chemical combustion reactions
  (            ⅆ      Qb              ⅆ      θ        )is equal to the sum of the variation of internal energy of the system (dE/dθ), of the mechanical power exchanged with the outside by means of the piston (dL/dθ) and of the amount of heat which is lost in contact with the cooled walls of the chamber
      (                  ⅆ        Qr                    ⅆ        θ              )          :
                                          ⅆ            Qb                                ⅆ            θ                          =                                            ⅆ              E                                      ⅆ              θ                                +                                    ⅆ              L                                      ⅆ              θ                                +                                    ⅆ              Qr                                      ⅆ              θ                                                          (        3        )
By approximating the fluid to a perfect gas of medium temperature equal to T, E=mcvT, wherefrom, in the absence of mass fluids, it results that:
                                          ⅆ            E                                ⅆ            θ                          =                  m                                                                          c            v                                                        ⅆ              T                                      ⅆ              θ                                                          (        4        )
The power transferred to the piston is given by
                                          ⅆ            L                                ⅆ            θ                          =                  p                                              ⅆ              V                                      ⅆ              θ                                                          (        5        )
By finally exploiting the status equation, the temperature can be expressed as a function of p and V:
                    T        =                  pV          mR                                    (        6        )
By differentiating this latter:
                                          ⅆ            T                                ⅆ            θ                          =                                            p              mR                                                                  ⅆ                V                                            ⅆ                θ                                              +                                    V              mR                                                                  ⅆ                p                                            ⅆ                θ                                                                        (        7        )
By suitably mixing the previous expressions, the following expression is reached for the dissipation law of the heat:
                                          ⅆ            Qb                                ⅆ            θ                          =                                            [                                                                    c                    v                                    /                  R                                +                1                            ]                                    p                                                      ⅆ                V                                            ⅆ                θ                                              +                                    [                                                c                  v                                /                R                            ]                                    V                                                      ⅆ                p                                            ⅆ                θ                                              +                                    ⅆ              Qr                                      ⅆ              θ                                                          (        8        )
By measuring the pressure cycle, being known the variation of the volume according to the crank angle and by using the status equation, it is possible to determine the trend of the medium temperature of the homogeneous fluid in the cylinder.
This is particularly useful in the models used for evaluating the losses of heat through the cooled walls
            ⅆ      Qr              ⅆ      θ        .
By finally substituting V(θ), p(θ) and
      ⅆ    Qr        ⅆ    θ  in the previous equation the dissipation law of the heat is obtained according to the crank angle
                    ⅆ        Q                                            b              ⅆ      θ        .
The integral of
            ⅆ      Q                              b        ⅆ    θ  between θi and θf, combustion start and end angles, provides the amount of freed heat, almost equal to the product of the combustible mass mc multiplied by the lower calorific power Hi thereof.
                              Q                                                              b                =                                            ∫                              θ                                                                                i                                            θ                                                                                f                                                                                ⅆ                    Q                                                                                b                                                  ⅆ                  θ                                                                                ⅆ                θ                                              ≅          mcHi                                    (        9        )
This approximation contained within a few % depends on the degree of completeness of the oxidation reactions and on the accuracy of the energetic analysis of the process. Deriving with respect to θ the logarithm of both members of the previous equation, one obtains the law relating how the burnt combustible mass fraction xb (θ) varies.
                                          1                                                           Q                                                                                b                                                                                ⅆ                Q                                                                                b                                      ⅆ              θ                                      =                                            1                              m                c                                                                                ⅆ                                  m                  c                                                            ⅆ                θ                                              =                                                                      ⅆ                                      x                    b                                                                    ⅆ                  θ                                            ⇒                                                                    ⅆ                    Q                                                                                b                                                  ⅆ                  θ                                                      =                                          m                c                                          Hi                                                                                ⅆ                                      x                    b                                                                    ⅆ                  θ                                                                                (        10        )
The combustible mass fraction xb (θ) has an S-like form being approximable with sufficient precision by an exponential function (Wiebe function) of the type:
                              x                                                              b                =                  1          -                      exp            [                          -                                                a                                                        (                                                                  θ                        -                        θⅈ                                                                                θ                                                                                f                                                -                        θⅈ                                                              )                                                                    m                  +                  1                                                      ]                                              (        11        )            with a suitable choice of the parameters a and m. The parameter a, called efficiency parameter, measures the completeness of the combustion process. Also m, called form factor of the chamber, conditions the combustion speed. Typical values of a are chosen in the range [4.605; 6.908] and they correspond to a completeness of the combustion process for (θ=θf) comprised between 99% and 99.9% (i.e. xb ε[0.99; 0.999]). From FIGS. 8 and 9 it emerges that for low values of m the result is a high dissipation of heat in the starting step of the combustion (θ−θi<<θf−θi) to which a slow completion follows, whereas for high values of m the result is a high dissipation of heat in the final step of the combustion.
In synthesis, the simplest way to simulate the combustion process in a Diesel engine is to suppose that the law with which the burnt-fuel fraction xb varies is known. The xb can be determined either with points, on the basis of the processing of experimental surveys, or by the analytical via a Wiebe function. The analytical approach has several limits. First of all, it is necessary to determine the parameters describing the Wiebe function for different operation conditions of the engine. To this purpose, the efficiency parameter a is normally supposed to be constant (for example, by considering the combustion almost completed, it is supposed a=6.9) and the variations of the form factor m and of the combustion duration (θf−θi) are calculated by means of empirical correlations of the type:m=mr(τa,r/τa)0.5(p1/p1,r)(T1,r/T1)(nr/n)0.3θf−θi=(θf−θi)r(Φ/Φr)0.6(nr/n)0.5  (12)where the index r indicates the data relating to the reference conditions, p1 and T1 indicate the pressure and the temperature in the cylinder at the beginning of the compression and τa is the hangfire. An approach of this type covers however only a limited operation field of the engine and it often requires in any case a wide recourse to experimental data for the set-up of the Wiebe parameters. A second limit is that it is often impossible for a single Wiebe function to simultaneously take into account the premixed, diffusive step of the combustion. The dissipation curve of the heat of a Diesel engine is in fact the overlapping of two curves: one relating to the premixed step and the second relating to the diffusive step of the combustion. This limit of the analytic model with single Wiebe has been overcome with a "single area" model proposed by N. Watson:xb(θ)=βf1(θ, k1, k2)+(1−β)f2(θ, a2, m2)  (13)
In this model β represents the fuel fraction which burns in the premixed step in relation with the burnt total whereas f2(θ, a2, m2) and f1(θ, k1, k2) are functions corresponding to the diffusive and premixed step of the combustion. While f2(θ, a2, m2) is the typical Wiebe function characterized by the form parameters a2 and m2, the form Watson has find to be more reasonable for f1(θ, k1, k2) is the following:
                              f1                                (                          θ              ,              k1              ,              k2                        )                          =                  1          -                                    [                              1                -                                                      (                                                                  θ                        -                                                  θ                                                                                i                                                                                θ                                                                                f                                                -                                                  θ                                                                                i                                                                                )                                    k1                                            ]                        k2                                              (        14        )
Also in this approach, a large amount of experimental data is required for the set-up of the parameters (k1; k2; a2; m2) which characterize the xb (θ) in the various operating points of the engine.
Both the model with single Wiebe and that of Watson are often inadequate to describe the trend of xb in Diesel engines supplied with a multiple fuel injection. FIG. 10 reports the typical profile of an HRR relating to our test case: Diesel Common Rail engine supplied with a double fuel injection.
This HRR, acquired in a test room for a speed=2200 rpm and a double injection strategy (SOI; ON1; DW1; ON2)=(−22; 0.18; 0.8; 0.42), is in reality a medium HRR, since it is mediated on 100 cycles of pressure. Both in the figures and in the preceding relations, while the SOI parameters (Start of Injection) is measured in degrees of the crank angle, the parameters ON1 (duration of the first injection, i.e. duration of the "Pilot"), DW1 (dead time between the two injections, i.e. "Dwell time") and ON2 (duration of the second injection, i.e. duration of the "Main") are measured in milliseconds as schematized in FIG. 11.
From a first comparison between FIGS. 7 and 10, the absence or at least the non clear distinguishability is noted, in the case of the HRR relating to a double fuel injection, of a pre-mixed and diffusive step of the combustion. A more careful analysis suggests the presence, however, of two main steps in the described combustion process. These two steps are called "Pilot" and "Main" of the HRR. The first step develops between about −10 and −5 crank angle and it relates to the combustion primed by the "Pilot".
The second one develops between about −5 and 60 crank angle and it relates to the combustion part primed by the "Main". In each one of these two steps it is possible to single out different under-steps difficult to be traced to the classic scheme of the pre-mixed and diffusive step of the combustion process associated with a single fuel injection.
Moreover the presence of the "Pilot" step itself is not always ensured, and if it is present, it is not sure that it is clearly distinguished from the "Main" step. FIGS. 12 and 13 summarize what has been now exposed. From the figures it emerges that for small values of SOI, i.e. for a pronounced advance of the injection, it is not sure that the "Pilot" step of the combustion is primed.
In conclusion, the models used for establishing xb in a single injection Diesel engine are often inadequate to describe the combustion process in engines supplied with a multiple fuel injection.
When the number of injections increases, the profile of the HRR becomes more complicated. The characterizing parts of the combustion process increase, and the factors affecting the form and the presence itself thereof increase. Under these circumstances, a mode, which effectively establishes the xb trend, should first be flexible and general.
That is, it adapts itself to any multiple fuel-injection strategy, and thus to any form of the HRR. In second place, the model reconstructs the mean HRR, relating to a given engine point and to a given multiple injection strategy, with a low margin of error. In so doing, the model could be used for making the map injection control system closed and dynamic.
Therefore, a need has arisen for a virtual combustion sensor for a real-time feedback in an injection management system of a closed-loop type for an engine (closed loop EMS).

Soft-computing method for establishing the heat dissipation law in a diesel common rail engine


Check valve package for pb-free, single piece electronic modules, the package having an exterior and an interior, and at least one electronic device mounted within the interior of the package electrically connected to a lead-free solder ball grid array on a surface of the package, the package having a check valve between the interior and exterior of the package configured to allow flow from the interior to the exterior and to prevent flow form the exterior to the interior. The package withstands the solder reflow temperatures for the reflow of the pb-free solder balls of a ball grid array packaging of an NVSRAM during mounting on a circuit board. The package is suitable for packaging circuits containing rechargeable batteries and for packaging other electronic devices.

1. Field of the Invention
The present invention relates to the field of electronic packaging.
2. Prior Art
Maxim Integrated Products, Inc., through its wholly owned subsidiary, Dallas Semiconductor, has introduced the SPM product family that is a manganese lithium battery backed NVSRAM (nonvolatile static RAM). The product is unique to the industry in that the battery used to backup the SRAM is reflowable, that is, will withstand the solder reflow temperatures required for mounting onto a circuit board. Therefore the battery can be onboard the module during customer reflow. This is opposed to current systems of competitors where the battery must be attached by hand after reflow, since until recently no battery existed that could take reflow temperatures (235 C). An enclosure around the battery is required because it cannot withstand a customer water wash in its bare form. This would expose the battery to mobile ionics and eventually short the battery. For a standard eutectic reflow profile where the package is not expected to exceed 235 C, this package is qualified.
235 C is the maximum temperature requirement for reflow of lead (Pb) containing solder. However for lead free solder, exposure to a reflow temperature of 260 C may be required. For the battery package in the SPM product family, a temperature of 260 C tends to diminish the integrity of the battery enclosure, providing the opportunity of moisture intrusion over time that may cause malfunction or premature failure of the battery backup.

Check valve package for Pb-free, single piece electronic modules


A centrifugation injection mold comprising: a lower mold portion having a basic block the lower portion of which is mounted to and rotates within bearing means that are affixed to a machine structure, a plurality of axial columns the bottom portions of which are affixed around the outer portions of the basic block, and a moveable block defining a lower mold cavity and being mounted in a sliding relationship to the axial columns, in order to be axially displaced between an open mold position and a closed mold position; an impelling means operatively associated with the machine structure and with the moveable block for displacing the moveable block to the open mold position against the action of an elastic means; a locking means mounted to each axial column; and an upper mold portion to be removably seated on the axial columns and affixed thereto by the locking means in a closed mold position.

It is already known from the prior art the centrifugation injection of the aluminum cages in rotors, which are formed by a stack of overlapped annular steel laminations provided with openings that are longitudinally aligned with the openings of other laminations of the stack, in order to define a plurality of axial channels interconnecting the external faces of the end laminations of the stack and which are angularly spaced from each other along a circular alignment, which is concentric to the longitudinal axis of the lamination stack, but radially spaced back in relation to the lateral face of the latter.
The lamination stack, with the longitudinal axis vertically disposed, is positioned inside a mold which defines a lower annular cavity close to the external face of the lower end lamination, and an upper cavity, which is substantially cylindrical or frusto-conical, close to the external face of the upper end lamination and opened to the inlet channel for the admission of aluminum into the mold.
During the aluminum pouring, the lamination stack has its central axial bore, into which will be later mounted the shaft of the electric motor, filled with a core having an upper end substantially leveled with the upper end lamination of the lamination stack, and a widened lower end portion seated on a respective lower end widening of the central axial bore of the lamination stack and against the mold portion that defines the lower cavity.
The aluminum is poured into the upper cavity, passing through the axial channels of the lamination stack to the lower cavity, filling the latter, the axial channels and the upper cavity, in this order, solidifying in a radial inward upward pattern, as the mold rotates around its vertical axis and the metals cools.
Upon completion of the aluminum pouring and solidification, the mold is opened and the formed rotor is submitted to one or more operations to eliminate the inlet channel and unobstruct the adjacent end of the central axial bore of the lamination stack, and to define the correct internal profile for the upper ring of the aluminum cage, which further comprises in a single piece, a lower ring already formed by the mold, and a plurality of bars formed inside the axial channels of the lamination stack.
In the centrifugation injection of these rotors, the upper and lower cavities of the mold and the lamination stack itself are heated, so that the aluminum passes through the upper cavity and through the axial channels of the lamination stack without solidifying, by gravity reaching the lower cavity, filling it and starting to solidify from the outside to the inside, and from the bottom upwardly, while the mold remains rotating.
In order to allow the injection mold, which involves and locks the upper and lower portions of the lamination stack, to rotate around its vertical longitudinal axis, the upper and lower cavities of the mold are mounted, respectively, to an upper bearing and to a lower bearing that are carried by the structure of the injection equipment.
In the molds of the above mentioned type, the deviations of concentricity and parallelism that occur between the axes of the upper and lower cavities cause vibrations in the mold and in the lamination stack during the rotation of the mold, which vibrations actuate in the metallic material being solidified in the upper and lower cavities.
A major problem caused by said vibrations of the rotating mold during the solidification of the aluminum is that the bars of the cage, which are formed inside the axial channels of the lamination stack, and even the rings, tend to present cracks, the bars being transversally broken in the interior of the lamination stack in a manner not perceived by external visual observation of the finished rotor. The rupture or crack of one or more bars or of the upper and lower rings of the cage considerably impairs the quality of the rotor and consequently the efficiency of the electric motor to be formed.
One of the possibilities to minimize or even eliminate the loss of quality by undue vibrations of the mold during the solidification of the aluminum is to mount the two cavities of the mold on a single lower bearing, whereby the axes of the two mold parts are united. However, in this solution, the upper and lower cavities of the mold are guided by columns affixed to the lower cavity. The upper cavity is axially displaced, guided by the columns, to open and close the mold, whereby the upper cavity is retained in a sliding relationship with the columns, considerably limiting the automation of the operations of loading the lamination stack in the mold and extracting the centrifuged rotor, besides causing problems of concentricity and rotor strike.
While the mounting of the two mold cavities on a single lower bearing assembly allows eliminating the problem of cracks in the parts of the aluminum cage caused by deviations of concentricity and parallelism between the axes of the two mold cavities, this known prior art mold still maintains the upper mold cavity mounted to the columns which are axially and eccentrically projected from the lower cavity, when said upper mold cavity reaches the open mold position for the loading of the lamination stack or removal of the centrifuged rotor. Thus, the movement of the lamination stack in and out of the mold must be effected by passing the lamination stack radially through the gap formed between two consecutive columns. This characteristic of the solutions in which there is only one lower bearing and the upper cavity is axially displaced along the columns between the open and closed mold positions requires complex solutions to reach a high degree of automation in the production of the rotors with a short cycle time, impairing the productivity.

Empresa Brasileira De Compressores S.A. - Embraco


An error-correcting code processing method includes: calculating descending symbols or ascending symbols or both, and calculating, as a parity, exclusive OR of all elements of an information symbol sequence; one or both of calculating exclusive OR for each element of the descending symbols, to generate low-order n bits of the descending symbols and calculating exclusive OR for each element of the ascending symbols, to generate low-order n bits of the ascending symbols; one or both of calculating exclusive OR of elements obtained by selecting, in descending order, elements from an element sequence resulting from arranging parities, to generate a high-order m bit of the descending symbols and calculating exclusive OR of elements obtained by selecting, in ascending order, elements from the element sequence, to generate a high-order m bit of the ascending symbols; and outputting the descending symbols or the ascending symbols or both as check symbols or a syndrome.

Because there is always a possibility that a transmission error occurs in the field of information transmission, a means to detect and correct an error is needed. In an application field where a probability that a single error occurs during transmission (hereafter, referred to as a bit error rate) is relatively low, a coding scheme such as the extended Hamming coding scheme and high-dimensional parity coding scheme that has high coding efficiency and transmission efficiency is employed (see Non Patent Literatures (NPLS) 1 to 3).
FIG. 1 shows a general procedure for information transmission involving error correction. When a transmission system transmits information symbols X to a receiving system, the transmission system first generates a code word Y by adding, to the information symbols X, check symbols for error correction, using a coding device, and transmits the code word Y to the receiving system. Here, there is a possibility that a transmission error (E) occurs on a communication path due to disturbance, and part of a value of the code word Y changes. The code word received by the receiving system is denoted by Y′. FIG. 2 shows a relationship among the transmitted information symbols, check symbols, and code word. A code word having a length of N that is obtained by adding check symbols having a length of N−L to information symbols having a length of L is referred to as an (N, L) code. In addition, L/N is referred to as a code rate of the (N, L) code.
FIG. 3 shows a procedure for decoding and error correction. The receiving system decodes the received code word Y′, calculates information called a syndrome for error detection and correction, and checks whether or not the received code word Y′ includes a transmission error. When finding out that the code word Y′ includes a correctable error, the receiving system corrects the information symbols. Information symbols to be outputted by the decoding and error correcting circuit are denoted by Z. There are four scenarios below for an error included in the information symbols Z to be outputted, depending on the capability of an employed error detection and correcting scheme. The following describes a coding scheme which enables single error correction and double error detection.
(1) When an error does not occur on a transmission path, a decoding and error correcting circuit determines that a received code word Y′ does not include the error (Y′=Y).
(2) When an error (single error) that can be detected and corrected by a decoding and error correcting circuit occurs on a transmission path, the decoding and error correcting circuit can detect the single error included in a received code word Y′ and correct the single error to a correct value.
(3) When an error (double error) that can be detected but cannot be corrected by a decoding and error correcting circuit occurs on a transmission path, the decoding and error correcting circuit can detect the double error included in a received code word Y′ but cannot correct the double error to a correct value.
(4) When an error (at least 3-bit error) that cannot be detected by a decoding and error correcting circuit occurs on a transmission path, the decoding and error correcting circuit cannot detect the error included in a received code word Y′ and thus cannot correct the error to a correct value.
The following describes a coding and decoding method in the extended Hamming coding scheme that enable single error correction and double error detection are used, and an elementary operation used in the coding and decoding method. A single error correcting method in which simple Hamming codes are used is first described, and the extended Hamming coding scheme that enables single error correction and double error detection is then described.
(1-1) Coding and Decoding in which Hamming Codes are Used
A Hamming code is a (2n−1, 2n−1) code that constitutes a code word obtained by adding n-bit check symbols to information symbols having a length of L=2n−n−1 bits, and is a single error correcting code. For instance, when n=4, a (15, 11) code is calculated. Information symbols X and a code word Y are expressed below by Equation 1 and Equation 2, respectively.[Math. 1]X=[xL−1,xL−2, . . . ,x0],L=2n−n−1  (Equation 1)[Math. 2]Y=[yN−1,yN−2, . . . ,y0],N=2n−1  (Equation 2)
In the Hamming coding scheme, a generator matrix G is used for coding, and a check matrix H is used for decoding. The check matrix H is an n×(2n−1) matrix where each column includes all of n-dimensional column vectors except all zeros. FIG. 4 shows an exemplary check matrix H in the Humming coding scheme when n=4. The columns of the check matrix H may be arranged in any manner.
The generator matrix G corresponding to the check matrix H is a matrix that satisfies properties expressed by Equation 3. However, all additions (exclusive OR operation) are performed in modulo 2. GT and HT represent a transposed matrix of G and a transposed matrix of H, respectively. Hereafter, when a superior letter of a character representing a matrix is T, the character with the superior letter represents a transposed matrix of the matrix.[Math. 3]HGT=(GHT)T=0  (Equation 3)
When the check matrix H is expressed by Equation 4, a coding scheme is referred to as a systematic coding scheme.[Math. 4]H=[AIn]  (Equation 4)
Here, A represents a given n×(2n−n−1) matrix, and In represents an n×n identity matrix. In the systematic coding scheme, the generator matrix G corresponding to the check matrix H is easily determined by Equation 5.[Math. 5]G=┌IHLAT┐  (Equation 5)
Here, m=2n−n−1, and AT represents a transposed matrix of A. FIG. 5 shows the generator matrix G corresponding to the check matrix H shown by FIG. 4.
Coding is performed by multiplying the information symbols X by the generator matrix G. A code word obtained by coding the information symbols X is denoted by Y. For example, a code word corresponding to X=[10110111011] is Y=[101101110111100] as shown by FIG. 6.
Decoding and error correcting are performed in the following manner. It is assumed that a received code word is denoted by Y′, and the received code word includes at most a single error. Here, a syndrome S of the received code word Y′ is defined by Equation 6.[Math. 6]S=Y′HT  (Equation 6)
Whether or not the received code word includes an error is determined based on a value of the syndrome S in the following manner.
When all elements of S are 0, it is determined that the received code word has not included the transmission error.
When S includes an element that indicates a value other than 0, it is determined that the error has been at a location in a column of H that matches a vector obtained by transposing S.
For instance, in the above example, assuming that the transmission error occurs at the 8th bit from the left of the received code word and that the received code word is Y′=[101101100111100], a syndrome is S=[0111] as shown by FIG. 7. A transposed vector of S matches a value of the 8th column from the left of the check matrix H, and thus it is clear that the error is at the 8th bit from the left of the received code word. (Note that the location at which the bit error occurs is underlined.)
(1-2) Coding and Decoding in which Extended Hamming Codes are Used
Using Hamming codes enables single error correction. However, when a double error occurs, it is impossible to determine whether a single error or double error occurs, and thus correction cannot be performed accurately.
Extended Hamming codes obtained by extending Hamming codes are used as a method of performing single error correction and double error detection. A code word in the extended Hamming coding scheme is obtained by adding, to a code word resulting from coding using the generator matrix G, a parity bit of the whole code word (exclusive OR of all bits of the code word). Thus, a code word length in the extended Hamming coding scheme is 2n.
In the above example, a parity of the code word [101101110111100] obtained by applying the generator matrix G to the information symbols X=[10110111011] is 0, and thus 0 is added to the end of the code word to generate Y=[1011011101111000].
Decoding and error detection and correction in the extended Hamming coding scheme are performed using an extended check matrix H′ obtained by adding a column vector whose all elements are 0 after the last column of the check matrix H in the original Hamming coding scheme, and adding a vector whose all elements are 1 below the last row of the check matrix H. FIG. 8 shows the extended check matrix H′ corresponding to the check matrix H shown by FIG. 4.
When the error occurs at the 8th bit from the left of the code word in the example, the received code word is Y′=[101101100111100]. When a syndrome Y′H′T is calculated for the code word Y′ using the extended check matrix, [01111] is obtained as shown by FIG. 9.
A transposed vector of [01111], the multiplication result, matches a value of the 8th column from the left of the extended check matrix, and thus it is clear that the error occurs at the 8th bit from the left of the received code word. When the received code word includes a double error, the last element of Y′H′T is 0, because even numbers of 1 are included in the received code word. All the elements of the last row of the extended check matrix are 1, and thus a column vector obtained by transposing the check result does not match any column of the extended check matrix. In this case, it is determined that the double error has occurred. When an at least 3-bit error occurs, it is impossible to detect the at least 3-bit error. The above description can be summarized into <Case 1> to <Case 3> indicated below. Hereafter, a syndrome is represented by S=[sn−1, sn−2, . . . , s1, 0, r]. In addition, or (element 1, element 2, . . . , element n) is a logic function for calculating a logical sum of all elements.
<Case 1> When all elements of S are 0 (r=0 and or (sn−1, sn−2, . . . , s1, s0)=0), it is determined that an error has not occurred.
<Case 2> When the element r=1 in S, it is determined that a single error has occurred. A location where the error occurs is an element corresponding to a column having a pattern that matches S.
<Case 3> In a case other than <Case 1> and <Case 2> (r=0 and or (sn−1, sn−2, . . . , s1, s0)=1), it is determined that a double error has occurred.
Next, conventional methods of implementing a device for coding and a device for decoding and error correcting can be classified into the following two types: (A) Implementation using software on a general-purpose processor (hereafter, referred to as a conventional method (A)); and (B) Implementation using dedicated hardware (ASIC: Application Specific Integrated Circuit) (hereafter, referred to as a conventional method (B)).
FIG. 10 is a diagram showing implementation of conventional error-correcting code processing, using software on a general-purpose processor. In FIG. 10, an instruction memory 111 and a data memory 112 are outside of a general-purpose processor 110. The instruction memory 111 holds instructions for coding operations and decoding operations in the error-correcting code processing. The general-purpose processor 110 performs a coding operation and a decoding operation in the error-correcting code processing according to an instruction read from the instruction memory 111. Moreover, the general-purpose processor 110 reads data held in the data memory 112 via a data bus 113, according to an instruction read from the instruction memory 111. Furthermore, the general-purpose processor 110 stores the results of the operations performed, into the data memory 112 via the data bus 113.
FIG. 11 is a diagram showing implementation of the conventional error-correcting code processing, using a general-purpose processor and a dedicated peripheral circuit (ASIC). In FIG. 11, an instruction memory 121, a data memory 122, a coding circuit 123, and a decoding circuit 124 are outside of a general-purpose processor 120. The instruction memory 121 holds instructions for coding operations and decoding operations in the error-correcting code processing. The general-purpose processor 120 reads data and a command specifying a process to be performed that are held in the data memory 122 via a data bus 125, according to an instruction read from the instruction memory 121, and transmits the command and data to the coding circuit 123 and the decoding circuit 124 via the data bus 125. Moreover, the general-purpose processor 120 reads, from the coding circuit 123 and the decoding circuit 124, status information indicating whether coding and decoding are possible or the like and the results of operations after the coding and decoding, and stores the status information and the results of the operations into the data memory 122 via the data bus 125. The coding circuit 123 performs a coding operation in the error-correcting code processing according to an instruction read from the instruction memory 121. The decoding circuit 124 performs a decoding operation in the error-correcting code processing according to an instruction read from the instruction memory 121. Here, the coding circuit 123 and the decoding circuit 124 include the ASIC. In addition, the coding circuit 123 generates check symbols, and the decoding circuit 124 generates a syndrome and corrects an error.
The following trade-offs exist between the convention methods (A) and (B).
In comparison with the conventional method (B), the conventional method (A) has the following advantages: (a) a smaller hardware amount required for implementation (it is sufficient to provide only a memory for storing programs.); and (b) more flexibility in responding to a change of specifications (it is possible to easily respond to a change of a coding scheme or a code length.).
However, in comparison with the convention method (B), the conventional method (A) has the following disadvantages: (c) a longer execution time (a larger number of execution cycles); and (d) a larger power consumption.

Error-correcting code processing method and device


An elevator installation and a method of operating the elevator system for temporary transportation of an overload within the elevator installation includes a car and a counterweight interconnected by one or more suspension ropes engaging a traction sheave that is driven by a motor. The traction between the suspension ropes and the traction sheave is enhanced independently of the counterweight for intended overload operation.

In order to maximize installation efficiency while maintaining cost-effectiveness, elevators are conventionally designed and commissioned to operate within predetermined nominal operating conditions, such as rated load and speed, to satisfy the specified transport requirements for a specific installation.
There are, however, temporary and infrequent occasions when it would be useful for the building owner to be able to operate the elevator outside of the nominal operating conditions e.g. for transporting a heavy article, such as an electrical transformer, that would otherwise overload the elevator.
Conventionally, a solution has been used whereby the mass of the counterweight is increased in proportion to the intended overload of the car so as to maintain the balancing factor between the car and counterweight. After the overload has been transported to the desired location, the additional mass is removed from the counterweight and the elevator can be returned to normal operation.
An alternative solution has been described in WO-A1-2011/039405 wherein an additional hoist is attached to the elevator car to supplement the existing elevator drive and thereby compensate for the overload. As with the previous example, after the overload has been transported to the desired location, the additional hoist can be detached from the car and the elevator can be returned to normal operation.
In both the methods described above the technician is required to attach additional equipment to an elevator component which is designed to move substantial distances within the hoistway, such as affixing a substantial additional mass to the counterweight or attaching an additional hoist to the elevator car. Not only are these procedures time-consuming and cumbersome but they can also be inherently dangerous. Furthermore, in the first procedure described above, the additional mass is generally added to the counterweight from the pit of the elevator installation. The resultant severely overbalanced elevator is then moved by the drive so that the overload, e.g. transformer, can be loaded into the empty car from the ground floor. This severely unbalanced trip requires the drive to produce and the motor to consume substantially larger electrical currents than during normal operation which can greatly reduce the lifespan of both electrical components.

Moving a heavy overload with an elevator


A system and method includes modules for determining whether an instruction is a target of a non-sequential fetch operation with an expected numerical property value, and avoiding execution of the instruction if it is the target of the non-sequential fetch operation and does not have the expected numerical property. Other embodiments include encoding an instruction with a functionality that is a target of a non-sequential fetch operation with an expected numerical property value. Instructions with the same functionality that are not targets of non-sequential fetch operations can be encoded with a different numerical property value. More specific embodiments can include a numerical property of parity, determining whether the instruction is valid, and throwing an exception, setting status bits, sending an interrupt to a control processor, and a combination thereof to avoid execution.

Many electronic devices use processors (e.g., a central processing unit (CPU)) and a memory to perform various functions. For example, embedded processors in certain routers may be responsible for data-plane processing tasks and for network traffic flows (propagating through the routers). The processors may facilitate baseline packet routing operations, including Layer 2 and Layer 3 forwarding, quality-of-service (QoS) classification, policing and shaping, security access control lists (ACLs), and loadbalancing. Due to high consumer demand, there is a push to pack more functionalities into electronic devices, while concurrently, device sizes are either remaining constant or becoming smaller.
As more functionalities are packed into smaller footprints, there is a demand for more efficient and reliable processors that can facilitate the myriad functionalities of the electronic device. For example, certain processors can consolidate a multitude of customized packet-processor cores (e.g., running at 900 MHz to 1.2 GHz) into a single piece of silicon, and thereby, reducing the use of external service blades inside the router. Such high performance processors may benefit from efficient and robust instruction set architectures for reliable system operations.

System and method for checking run-time consistency for sequentially and non-sequentially fetched instructions


An optical connection component includes an optical fiber; a high relative refractive-index difference optical fiber that is fusion-spliced to the optical fiber and has a greater relative refractive-index difference to a cladding of a core than the optical fiber; and an accommodating member accommodating the entire length of the optical fiber and the high relative refractive-index difference optical fiber, and has a first end face on which an end face of the optical fiber on the side opposite to the fusion-spliced side is exposed to be substantially flush with the first end face, and a second end face on which an end face of the high relative refractive-index difference optical fiber on the side opposite to the fusion-spliced side is exposed to be substantially flush with the second end face. The optical fiber and the high relative refractive-index difference optical fiber are fixed to the accommodating member.

The present disclosure relates to an optical connection component.
In the related art, in an optical waveguide constituting an optical element such as a planar lightwave circuit (PLC), a silicon waveguide chip, and the like, reduction of the connection loss between the relevant optical waveguide and an optical fiber to optically connect has been mentioned as one of the issues. For this reduction of the connection loss, there is a need to reduce the mismatch of an MFD (Mode Field Diameter) between the optical waveguide, for which the MFD is extremely small relative to the connecting optical fiber, and the relevant connecting optical fiber. The MFD of the connecting optical fiber is, for example, approximately 10 μm at a wavelength of 1550 nm, and the MFD of the optical waveguide is, for example, less than or equal to 0.5 μm at a wavelength of 1550 nm.
As a technique for this purpose, an optical connection component that fusion-splices a high relative refractive-index difference optical fiber, for which a relative refractive-index difference to the cladding of a core is greater than the connecting optical fiber, to the connecting optical fiber and connects the optical waveguide of the optical element and the connecting optical fiber via this high relative refractive-index difference optical fiber has been disclosed (see Japanese Patent No. 6089147, for example). Normally, as the MFD of a high relative refractive-index difference optical fiber is closer to the MFD of the optical waveguide than the MFD of the connecting optical fiber and can be made to be, for example, 3 μm to 5 μm, by interposing the high relative refractive-index difference optical fiber between the connecting optical fiber and the optical waveguide, the connection loss can be reduced.
As the above-described optical element having the optical waveguide of a small mode field diameter is usually formed in small form, the optical connection component used together with this optical element also needs to be downsized. However, it is also important to maintain high reliability at the same time as downsizing.


A laser chamber has angled reflectors that reflect acoustic and shock waves away from the laser discharge area to minimize acoustic and shock wave disturbances. The angled reflector may have different configurations to assist in the dissipation of the acoustic and shock waves. For example, the angled reflector may have a modulated reflective surface, such as having grooves or holes defined within the surface. Further, the angled reflector may have a reflective surface with acoustic and shock wave absorbing properties. The reflective surface with absorbent properties may be a felt metal or have multiple layered porous surfaces. In addition, the walls of the laser chamber may be modulated to assist in the dissipation of the acoustic waves and shock waves through absorption, scattering, and by generating interference within the reflected waves. Multiple layered porous surfaces may be used along the walls to absorb and scatter incident waves. The walls of the laser chamber may also be covered with an acoustic and shock wave absorbing material, such as felt metal. In other embodiments, the walls of the laser chamber are modulated with grooves, such as triangular or rectangular horizontal grooves, which scatter incident waves and generate interference within reflected waves.

Pulsed laser systems, such as excimer lasers, are well known. FIG. 1 is a front view of laser chamber 10 used in a conventional pulsed laser system. As shown in FIG. 1, laser chamber 10 includes an electrode structure 12, a blower 14, a heat exchanger 26, a pre-ionizer 28, baffles 30 and a grounding screen 32, which is used to connect the lower of electrodes 12 to ground. A laser discharge area 24 is defined by electrode structure 12.
FIG. 2 is a side view of laser chamber 10. Laser chamber 10, as shown in FIG. 2, also includes windows 16, 18, and a laser beam 20.
As well known by those skilled in the art, a pulsed laser system, such as an excimer laser, produces high energy, high frequency pulses in a gas that is between electrodes 12 in laser chamber 10. The gas, which may contain krypton and fluorine, is maintained at high pressure, for example, 3 atm. Pre-ionizer 28 first floods the gas within discharge area 24 with free electrons (10.sup.6 to 10.sup.8 per cm.sup.3). Once the gas within discharge area 24 is conditioned with a sufficiently increased electron density, electrodes 12 produce a high energy discharge, which may be for example 15-50 kV. The lasing action from the high energy discharge occurs within 100 nsec from the time of discharge.
The high energy discharge in discharge area 24 produces a large amount of local heating in the gas. The thermal disturbance changes the index of refraction of the gas, which has a deleterious effect on the efficiency and energy of the laser system. The thermal disturbance in the gas does not affect the lasing action from the pulse that caused the thermal disturbance because the lasing action occurs within a short amount of time after the high energy discharge, approximately 100 nsec. However, subsequent high energy discharges, which occur at a frequency of approximately 1 to 2 KHz, will be produced in the highly disturbed, thermally energetic gas unless the gas is circulated within laser chamber 10. Thus, blower 14 is used to circulate the gas within laser chamber 10, while heat exchanger 26 is placed in the path of the gas flow to cool the gas as it circulates. Typically, the gas in laser chamber 10 is circulated with a flow velocity of 25-30 meters per second, however this amount is dictated by the frequency of the pulsed laser system.
When electrode structure 12 produces a high energy discharge an acoustic and/or shock wave is produced which then propagates outward from discharge area 24. An acoustic wave is a standing wave that is formed within the cavity of laser chamber 10 and that travels with the velocity of sound. Shock waves, on the other hand, are free standing waves that generate high pressure gradients and that travel at velocities greater than the velocity of sound.
The acoustic and shock waves propagate through the gas until they reach the walls 11 and 13 of laser chamber 10, at which time the acoustic and shock waves are reflected back into discharge area 24. The acoustic and shock waves are unwanted pressure changes in the gas that, when reflected back into discharge area 24, interfere with the energy efficiency and energy stability of the laser system. The degree to which the energy efficiency and energy stability are affected depends on pulse repetition frequency as these frequencies interact with the natural acoustic modes of the chamber.

Laser chamber with minimized acoustic and shock wave disturbances


A multiband satellite antenna is provided. The multiband satellite antenna includes a plurality of first band wave receivers and a second band wave receiver. The first band wave receiver includes a first band wave guide, and the second band wave receiver has a first receiving unit and a second receiving unit. The first receiving unit and the second receiving unit are disposed on opposite sides of an alignment line of the first band wave receivers. Each of the first receiving unit and the second receiving unit has a second band wave guide. Output ends of the first receiving unit and the second receiving unit are coupled together to combine signals received from both units into a single signal, and then the single signal is outputted as a second frequency signal. Through this design, in a high satellite density environment, dual-frequency signals from several satellites at similar elevation angles can be received by the antenna of the invention.

1. Field of the Invention
The present invention relates to a multiband satellite antenna; more particularly, the present invention relates to a multiband satellite antenna for receiving satellite signals.
2. Description of the Related Art
Recently, as the space technology advances, the applications of satellite bring more and more convenience into people's life. Satellites are widely applied in various technologies including, for example, explorations, weather forecasting, or global positioning, etc., and especially mature in signal transmissions. Satellites are used as a transmitting medium for signal transmissions in communication, data transmission, or video/audio broadcasting fields. However, as the demand of applying satellites to signal transmissions grows, the number of satellites and the available frequency bands should be increased accordingly.
In general, the common frequency bands for satellite communications include Ku frequency bands and Ka frequency bands. The Ka frequency band has a higher frequency and is less affected by terrestrial microwaves but seriously affected by rainfalls. The Ku frequency band has a lower frequency and is more affected by terrestrial microwaves but less affected by rainfalls. Current satellites include a wideband satellite, which can transmit signals of the two frequency bands simultaneously, and therefore, a corresponding antenna should have the ability to receive signals of the two frequency bands simultaneously. As shown in FIG. 1A, a traditional dual-frequency satellite antenna includes a wave receiving device 5, which has a Ka band wave guide 10 and a Ku band wave guide 20 disposed coaxially. The Ku band wave guide 20 has a larger inner diameter and surrounds the Ka band wave guide 10. A high frequency suppression module 30 is disposed outside the Ku band wave guide 20 for suppressing the high level mode in electric fields, so that the field pattern produced by the wave receiving device 5 can be smoother and more symmetrical. However, since the Ku band wave guide 20 is disposed coaxial with the Ka band wave guide 10, the inner diameter of Ku band wave guide 20 should be increased to correspond to the Ku frequency band. Therefore, the wave receiving device 5 has a larger volume according to this design.
In addition, taking geosynchronous satellites as an example, because the number of satellites keeps increasing while orbit positions are limited (360 degrees), consequently, the International Telecommunication Union (ITU) have changed the satellite distribution from every 3 degrees to every 2 degrees for one satellite. Due to the decrease in the included angle between satellites, the wave receiving device needs to be adjusted accordingly. FIG. 1B illustrates a traditional wave receiving device 7 capable of receiving signals from several satellites simultaneously. The wave receiving device 7 includes a Ku band wave guide 20 in the middle and Ka band wave guides 10 on two sides. In such a design, the satellite signals received at a same elevation angle are single frequency signals, and therefore, the wave receiving device 7 is not applicable to dual frequency satellite signals. Furthermore, in such a design, the space between the two Ka band wave guides 10 is limited, and therefore, only one Ku band wave guide 20 can be accommodated therein. Additionally, because the space between the two Ka band wave guides 10 is limited, the wave receiving device 5 of FIG. 1A cannot be disposed therein.


Methods, systems, and devices for wireless communications are described. In one example, a transmitting device may identify first and second portions of data to include in a data transmission. The transmitting device may encode the second portion by a configuration of a first subset of resource elements. The transmitting device may transmit, via the data transmission, first signals representative of the first portion over the first subset and one or more second signals over a second subset of resource elements. A receiving device may receive the data transmission and may identify that the one or more second signals include content other than data of the data transmission. The receiving device may decode the first signals in order to identify the first portion and the configuration in order to identify the second portion. The receiving device may refrain from decoding the one or more second signals based on the identifying.

Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple-access communications system may include one or more base stations or one or more network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE).
In some cases, a transmitting device may include a power amplifier (PA) to amplify signals before transmission. As a peak-to-average power ratio (PAPR) increases, the PA may produce increasingly distorted signals. To limit signal distortion, the input power of the signal may be limited to be below or near a back-off (BO) value. Such limitations may limit the capability of the transmitting device to perform wireless communications.

Spectral efficiency for tone reservation peak-to-average power ratio reduction


A display rack for displaying storage boxes for merchandise, comprising two vertical, spaced apart members attached to two horizontal base portions. Each vertical member has a slit cut in its top end for insertion of a sign. Each base portion has a slot cut therethrough on one side, so that the bottom end of a vertical member fits within the slot. There is also means for securing each base portion to a vertical member so that the vertical members slant slightly rearwardly from the vertical. Each base portion can be rotated to lie parallel with the vertical member to which it is secured. A plurality of spaced-apart horizontal beams are mounted between the two vertical members and attached to the rear side of each of the two vertical members. A plurality of spaced-apart horizontal support means are also mounted between the vertical members and beneath a corresponding horizontal beam, so that the distance between a horizontal support means and the corresponding horizontal beam is equal to the height of the box. The storage box can be detachably mounted on the rack by placing the rear wall of the box a behind a beam so that the rear wall of the box rests against the beam. The bottom of the box then rests on the support means, so that the bottom of the box is angled slightly downward from horizontal to display the merchandise contained therein.

1. Field of the Invention
This invention relates to a display rack for stackable boxes. In particular, this invention relates to a vertical, free-standing display rack that is adapted for attachment to boxes of flower bulbs or other products to display such boxes.
2. The Prior Art
Free-standing racks are commonly used in the retail industry to display various items for sale. These racks often comprise a series of horizontal bars connected by two vertical members that are mounted on a base. The items may be either hung directly on the racks, or placed in boxes or trays which are hung on the racks via hooks or pegs.
Often a bracket is mounted on the bars which is capable of mounting a storage box for display of merchandise. An example of such a display mechanism is shown in U.S. Pat. No. 4,228,906 to Jones, which shows an upright adjustable rail mounting assembly having flanges located on horizontal rails. Storage boxes are equipped with hooks which facilitate attaching the boxes to the flanged rails.
Another type of display system is shown in U.S. Pat. No. 3,181,703 to Dunham, which discloses a vertical display rack having a plurality of horizontal brackets mounted thereon. Storage boxes are mounted on the display rack by placing the rear wall of the box underneath the upper flange of the bracket and resting the bottom of the box on the bottom flange of the bracket.
Additional display systems are shown in U.S. Pat. No. 1,240,908 to Weis et al., and U.S. Pat. No. 1,446,036 to Dodd. These systems also show the mounting of storage boxes onto brackets for display on vertical racks.
While all of these systems are useful for displaying merchandise, they all suffer from drawbacks. First, it would be desirable to construct a display rack that does not require the use of many extra components, such as brackets, screws, etc., which must be attached to either the rack or the storage box before the box can be mounted. Second, it would also be desirable to construct a display rack whose base can be folded so that the rack lies completely flat for ease of transportation. Third, it would also be desirable to have a means for mounting a sign on the rack, to advertise the merchandise being displayed. Fourth, purely vertical display racks do not optimize the display capabilities of the storage boxes. A rack that is inclined slightly rearwardly from the consumer best displays the merchandise contained in the hanging storage boxes, and is better balanced than a purely vertical rack.

Simple Pleasures Flowerbulbs & Perennials, Inc.


A radar sensor system and method for vehicles. An example radar system includes a processor, a plurality of transceivers having antenna(e). The antenna of the transceivers are located at various points around the vehicle. The transceivers include receive and transmit electronics that are in signal communication with the corresponding antenna. The transmit electronics output radar signals via the antenna. The transmit electronics include a voltage controlled oscillator (VCO), a dielectric resonator oscillator (DRO), a phase locked loop (PLL) component and a direct digital synthesizer (DDS). The receive electronics receive from the antenna any radar reflections corresponding to the outputted radar signals and send signals associated with the radar reflections to the processor. The processor generates output signals based on the signals received from the plurality of transceivers.

There are multiple automotive, marine and aviation applications where small, low cost millimeterwave (MMW) radar sensors are distributed around a vehicle to provide functions, such as adaptive cruise control, anti-collision warning, brake applications, parking, marine threat detection or marine docking guidance.
Many developers have created low cost MMW sensors, particularly for the automotive marketplace where production numbers can be in the 100,000s. Most use modulation that is either FM/CW or UltraWideband. In the typical application, each sensor provides its own modulation and signal processing in a single package. Adding more sensors requires adding complete radar and signal processing/control systems to each location and then combining data from each in yet another computing platform. This duplicates many functions.
The RF implementation of the MMW Radar subsystems has either been overly complex (frequency multiplication systems) or overly simple with poor RF performance (MMW Oscillator directly connected to an antenna and modulated). Both systems generate very high phase noise and varying modulation characteristics over time and environmental changes.
U.S. Pat. No. 7,324,039 to Boltovets et al. attempts to generate a MMW radar signal by frequency multiplication of an open loop X band Voltage Controlled Oscillator. This choice for FM/CW modulation also directly multiplies any modulation non-linearity and causes phase noise to increase by a factor of 20 Log N where N is the multiplication factor. Both factors significantly degrade the performance of the resulting system.
Overly simple systems that employ a directly modulated MMW VCO to avoid the use of frequency multiplication achieve an overly sensitive VCO that is easily made non-linear by circuit effects, temperature or movement of objects present in the antenna beam.

Microwave and millimeterwave radar sensors


Enhancement of the reliability of an imaging device comprising several pixels is provided, each of the pixels comprising several first blocks of electronic components organized as a matrix and joined by links to row buses and column buses of the matrix allowing the powering and control of each of the first blocks for its nominal operation. Each of the pixels moreover comprises, associated with the first block, programmable means for disconnection of the first block from the at least one of the buses. Locating of a fault in a device is also provided, the fault occurring in one of the first blocks and leading to a generalized fault in several first blocks.

The invention relates to the enhancing of the reliability of a matrix of electronic elements and to a method for locating a fault in the matrix. The invention is especially useful in imaging devices and more particularly in a detector allowing image capture.
This type of device comprises a great number of sensitive dots called pixels generally organized as a matrix or strip. In an image detector, a pixel is the basic sensitive element of the detector. Each pixel converts an incident signal to which it is subjected, such as for example electromagnetic radiation, into an electrical signal. The electrical signals issued by the various pixels of a matrix are collected in succession during a read-out phase so that they can be processed and stored to form an image. The signal from each pixel can be digitized either inside the pixel, in which case the pixel delivers digital information, or digitization can also be performed downstream of the pixel, the pixel then delivering analog information.
The pixels are for example made up of a photosensitive area delivering a current of electric charges as a function of the stream of photons it receives, and an electronic circuit for processing this current. The photosensitive area generally includes a photosensitive element, or photodetector, which can for example be a photodiode, a photoresistor or a phototransistor. The photodetector is connected to an electronic circuit inside the pixel, i.e. arranged upstream of a read bus, the latter being able to collect information from adjacent pixels. Generally, connection between the pixel and the read bus is controlled in such a way that the reading of each pixel is organized. Thus, the pixel comprises a photodetector as well as electronic elements arranged upstream of said connection. There exist photosensitive matrices of large dimensions which can possess several million pixels.
A radiation detector can be used for imaging ionizing radiation, and particularly X- or γ-radiation, in the medical field or in the area of non-destructive testing in the industrial field, for the detection of radiological images. Photosensitive elements make it possible to detect visible or near-visible electromagnetic radiation. These elements are insensitive, or poorly sensitive, to radiation incident on the detector. For this reason, use is often made of a radiation converter known as a scintillator, which converts incident radiation, for example an X-ray, into radiation in a band of wavelengths to which the photosensitive elements in the pixels are sensitive. An alternative consists in producing the photosensitive element from another material performing the direct conversion of the X-ray into electric charges. Such is the case, for example, of matrices in which a first pixellated substrate made of cadmium telluride (CdTe) is connected pixel-by-pixel to a CMOS read-out circuit, which therefore no longer has a detection function.
Each pixel is made up of a block of electronic components which can be relatively complex. This block is linked to arrays of rows and columns of the matrix. These rows and columns guarantee the necessary bias, the control, and the output paths for the information detected by the pixel.
Faults in a matrix may affect either the arrays of rows and columns (short-circuits or open circuits) or the inside of the blocks of electronic components.
The risk of failure of a block increases when so-called critical components are incorporated into the pixel, i.e. components having a higher risk of failure than more standard components. These could be, for example, components making use of certain particular technological processes, or employing particular surfaces: for example, a high-capacitance capacitor can employ thin dielectric films, which may present local defects, or even be of large area, in which case it then runs the risk of being affected by dust during fabrication. Naturally, by increasing the number of pixels, the risk of a pixel failure increases.
To reduce this risk, it is possible to design components or connections inside the blocks with margins of safety over the minimum design rules. However, this limits the number of acceptable components per pixel and therefore the achievable operations.
One can nonetheless tolerate failures in isolated pixels. For example in an image detector, when a pixel is faulty, it is possible to reconstruct the missing information by averaging the items of information issued by neighbouring pixels.
However, failure in an isolated pixel, for example a short circuit, can pollute neighbouring pixels of a row or column, or even prevent the overall operation of the matrix.
To avoid this contagion efforts have been made to locate the defective pixels in order to isolate them by cutting the connections linking the affected blocks to the row or column buses, generally by laser fire. However, this technique has several limitations.                It is an additional technological step, requiring equipment and time, and therefore incurring a cost.        The use of laser fire presupposes knowledge of the position of the faulty pixel. However, in the case where the fault triggers the breakdown of a power supply, the fault before correction can trigger loss of functionality of a large part of the matrix, or even the entire matrix. Location is then difficult or impossible.        The use of laser fire requires the provision of spaces dedicated to laser cutting. This therefore takes up space in the pixels.        Laser fire can be used in the factory, but in practise is not feasible after-sale. It cannot therefore be used to combat faults appearing during the lifetime of the device.
As an alternative to laser fire, fuses incorporated into each pixel may be used. The limitations are broadly the same as for laser fire.

Electronic components matrix of enhanced reliability and method for locating a fault in the matrix

COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIE ALTERNATIVES


A debugging architecture includes a set of debug counters for counting one or more events based on a set of signals from a device being monitored. The architecture provides for observing the outputs of the debug counters during operation of the device. The outputs of the counters are provided to an output bus (e.g., a Debug Bus) via an output bus interface during operation of the device being monitored. A data gathering system can access the output bus in order to gather the data from the counters for analysis.

In order to perform debugging, many devices (e.g., computing systems) include a set of counters that track the number of times an event occurs (e.g., writes to RAM). Typically, the outputs of the counters are available via an interface, such as a CPU interface, that allows the values in the counters to be read like registers. Such an arrangement has several drawbacks. For example, the CPU generally must stop its operation to read the registers. Stopping the CPU alters the system behavior. It may also take many clocks for the CPU to read each register. This makes it difficult to use the counters to observe fine grained behavior such as pipeline stalls and to see how two behaviors are correlated.

Observing debug counter values during system operation


An underdrain block for a filter system comprises a housing that has of a top wall, a bottom wall, a first end wall, a second end wall, a first side wall, and a second side wall. The end walls and the side walls connect the top wall to the bottom wall. The bottom wall forms two lateral rows of support legs configured to straddle infrastructure of the filter system. One or more snap-locking mechanisms are located on the side walls so that adjacent underdrain blocks are interconnected by the locking mechanisms when snapped in place. In one embodiment, the first side wall comprises one or more tongue lugs and the second side wall comprises one or more groove lugs, each groove lug defines a groove for mating with the tongue lug so that adjacent housings are interconnected by the tongue-in-groove locking mechanisms when the tongue lugs are snapped into the grooves.

Water, wastewater, and industrial filtration units typically have an underdrain system for supporting filter media and to space the filter media apart from the bottom of the filter. In addition to providing support for the filter media, the underdrain system serves two primary purposes: to collect the filtered water that passes through the media and to uniformly distribute backwash water, backwash air, or a combination of both, across the filter.
Underdrain blocks are often made of pre-cast concrete blocks or concrete filled plastic jacketed blocks. The high-strength concrete blocks are placed side-by-side and end-to-end in the bottom of the filter to form a "false bottom". The blocks provide support for the filter media and are shaped to collect the filtered water that passes through the media.
In addition to shaping for collection, the blocks have conduits, commonly known as laterals, to allow for the passage of air or water used as a backwash. Piping, such as air headers, is part of the backwash air distribution system. Backwash water is brought into the system by flumes. Air headers bring in pressurized air, which is distributed into the laterals by pipes from the top of the headers, through the flumes and into the laterals.
During backwash operations, air is forced through the air distribution pipes and into the air laterals of the underdrain blocks. The pressurized air can be used as a backwash or combined with water for an air/water backwash. The pressurized air/water combination causes the filtered water to be passed upward through the media with sufficient velocity to prevent filter problems such as mud balls, filter cracking, agglomeration buildup on the media grains, and inactive areas within the filter. The underdrain blocks also act to physically separate the filter media from the air distribution pipes to prevent separate the air distribution pipes to prevent clogging of the orifices in the pipes by the finer particles of the filter media.
Problems can occur because the upward pressure against the blocks can be too forceful. Sometimes the pressure can fall within a range of 2 psi to 6 psi. Such strong pressure tends to dislocate the blocks, thereby allowing the filter media to drop into and damage the infrastructure. The cost of emptying the filter and realigning the blocks is high both in manpower and downtime of the filter.
U.S. Pat. No. 6,325,931 to Roberts discloses one example of an extruded underdrain block that is equipped with side rails. The side rails function to help align the blocks side-to-side in the filter basin. In one embodiment, the side rails on one side are offset from the side rails on the other side to allow the block to interlock with the adjacent block, eliminating the need for grout between the blocks.
U.S. Pat. No. 6,143,188 to Jantsch et al. discloses an underdrain block for a filter media system. The underdrain block is comprised of a top wall, a bottom wall, two side walls and plurality of interior walls. Jantsch also describes filling the gaps between the blocks with grout. The grout is used to hold the blocks together.
U.S. Pat. No. 4,923,606 to Gresh et al. Gresh et al. disclose underdrain blocks that are a combination of a plastic jacket and a concrete mold. The underdrain blocks of the '606 reference are used for both upflow and downflow filtration units. Thus the blocks provide for a distribution of both liquid and air during backwash operations.
U.S. Pat. No. 5,160,614 to Brown discloses an underdrain system comprised of a series of modular, interconnected air duct blocks. In the '614 reference, the row of air duct blocks extend transversely to a plurality of laterals. The laterals are defined by the connection of individual underdrain blocks in parallel adjacent rows. The air duct blocks are interconnected such that interiors of the separate air duct blocks are in fluid communication with one another to supply backwash gas through a single source of gas supply.
Because stability in the support surface is important during backwash, there is a need for an improved underdrain system that will limit the movement of the underdrain blocks during backwash procedures. Existing underdrain block designs offer either no features for backwash stability or only a limited amount of backwash stability through offset rails.


A leakage detecting device for an evaporated fuel gas system of an automobile draws and maintains a partial vacuum in the air space above the fuel in a tank 1 by temporarily connecting the space to the negatively pressurized intake manifold 5. An oxygen sensor 21 thereafter monitors the oxygen level in the evacuated space for a predetermined period of time, and if the oxygen increase exceeds a predetermined normal increase, a leakage alarm is given.

1. Field of the Invention
The present invention relates to a leakage detecting device for an airtight vessel which is employed for inspecting airtightness of, for instance, a fuel tank of an evaporated fuel gas treating device for an automobile or a piping system.
2. Discussion of Background
Conventionally, a leakage detecting device which is employed in an evaporated fuel gas treating device for an automobile, is constructed as shown in FIG. 2.
FIG. 2 is a construction diagram of a conventional leakage detecting device, which is disclosed in "Technical Support Document Jul. 26, 1991" issued by State of California Air Resources Board.
In FIG. 2, reference numeral 1 designates a fuel tank which is mounted on a car body of an automobile, not shown. Numeral 2 designates a canister which is constructed to adsorb evaporated gas from fuel inside the fuel tank 1, and which communicates with the top air space of the fuel tank 1 through a communicating pipe 3.
Numeral 4 designates an air cleaner for cleaning air sucked by an engine, not shown, and 5, an intake pipe connecting the air cleaner 4 to the engine, in which a throttle valve 6 is provided. Further, a portion downstream of the throttle valve 6 in the intake pipe 5, communicates with the canister 2 through a communicating pipe 7. The communicating pipe 7 is provided with a canister purge valve 8 by which the passage is opened and closed.
Numeral 9 is a pipe for communicating the canister 2 to the atmosphere, which is provided with a canister close valve 10. Numeral 11 designates a cap for sealing up the fuel tank 1 and 12, a canister protection valve connected to the fuel tank 1.
Numeral 13 designates a pressure sensor for detecting a pressure in the air chamber portion of the fuel tank 1 in performing a leakage check, mentioned later. This pressure sensor 13 communicates with the air chamber portion of the fuel tank 1 through a pressure communicating pipe 14, the pressure of which is outputted to a control circuit 15.
The control circuit 15 is constructed to control the opening and closing operation of the canister purge valve 8 and the canister close valve 10, and to perform the leakage check on portions from the fuel tank 1 to the canister purge valve 8 and the canister close valve 10 wherein the evaporated fuel gas flows. The leakage check is performed by decompressing the portions wherein the evaporated fuel gas flows, employing a negative pressure inside the intake pipe 5 and by monitoring a pressure change detected by the pressure sensor 13 during a constant time period.
Next, an explanation will be given of the operation of the above device.
Liquid fuel such as gasoline is stored in the fuel tank 1 and air is enclosed on the top side of the liquid surface of the fuel. It is necessary that the air portion communicates with the atmosphere such that the pressure in the fuel tank 1 does not become a negative pressure to an exceeding degree and air in the atmosphere can be introduced therein when the fuel is consumed.
Conversely, when the fuel tank 1 is heated by an atmospheric temperature elevation, sunlight and the like, the air in the fuel tank expands. Therefore, it is necessary to discharge the air in the fuel tank 1 to the outside. However, the air inside the fuel tank 1 contains the evaporated gas of fuel since the fuel normally contains a volatile component. Therefore, when the fuel containing the evaporated gas of fuel is discharged in the air, air contamination is caused. To avoid the air contamination, the air inside the fuel tank is led to flow to the intake pipe 5 through the communicating pipe 3, the canister 2, the communicating pipe 7 and the canister purge valve 8, from which the air is introduced to an engine and the fuel portion is combusted in the engine.
However, when the evaporated gas is introduced into the engine as above, the air-fuel ratio changes, which exerts a very unfavorable influence on the running of the engine especially when the engine is driven in a low output state. A control is performed to prevent the above drawback such that the air containing the evaporated gas does not flow to the engine when the engine is driven in the low output state. The control circuit 15 determines whether the running state of the engine is in the low output state, and closes the canister purge valve 8 when the engine is in the low output state.
At this moment, the control circuit 15 opens the canister close valve 10. In this way, the air containing the evaporated gas is removed of the evaporated gas by the canister 2 and the cleaned air is discharged to the atmosphere through the pipe 9 and the canister close valve 10.
When the canister 2 stores the evaporated gas, the evaporated gas catching function of the canister 2 is gradually saturated. Therefore, the evaporated gas inside the canister 2 flows into the engine, when the engine is in a high output running state and the canister purge valve 8 is opened, thereby purging the canister 2. When the engine is in the high output running state, air in the atmosphere is drawn into the canister 2 through the pipe 9 by employing the negative pressure inside the intake pipe 5. The evaporated gas in the canister 2 flows to the intake pipe 5 through the communicating pipe 7 and the canister purge valve 8 and is introduced to the engine, along with the air containing the evaporated gas from the fuel tank 1. This is the normal operation in the conventional evaporated fuel gas treating device.
However, a large amount of the evaporated fuel gas can be discharged to the atmosphere when the airtightness is lost wherein the cap 11 is not completely closed or some portion of the evaporated fuel gas treating device is destructed. In the conventional case, a leakage check is performed by employing the pressure sensor 13 to avoid such a disadvantage.
This leakage check is performed by decompressing the total evaporated fuel gas treating system by the intake negative pressure of an engine. The control circuit 15 controls the operations of the canister purge valve 8 and the canister close valve 10, and compares a pressure change quantity outputted from the pressure sensor 13 with a second pressure change quantity when the device is normal.
The control circuit 15 closes the canister close valve 10, when the engine is in the high output running state and the canister purge valve 8 is opened, once in a pertinent period of time, and changes the pressure inside the evaporated fuel gas treating device including the fuel tank 1 and the canister 2, into a negative pressure by employing the negative pressure inside the intake pipe 5. Thereafter, the control circuit 15 closes the purge valve 8 thereby generating a closed system in the evaporated fuel gas treating device, and monitors the output signal of the pressure sensor 13 for a certain duration of time.
At this occasion, the control circuit 15 compares a pressure increasing rate when the device is normal, with a second pressure increasing rate detected by the pressure sensor 13. When a rapid pressure increasing rate is recognized in comparison with the one when the device is normal, the control circuit 15 determines that there is a leakage in the system and alarms the operator. The leakage check has been performed as above.
However, the pressure sensor is generally expensive, and, therefore, there is a limitation in reducing the cost in the leakage detecting device employing the pressure sensor as stated above.

Leakage detecting device for an airtight vessel