Disclosed is an apparatus and method for generating a QCTC (Quasi-Complementary Turbo Code) considering a characteristic of a turbo code in a packet communication system or a communication system using an ARQ (Automatic Repeat reQuest) scheme by segmenting a length N of the QCTC into a predetermined number of sections, determining SPIDs (Sub-code Packet Identifications) corresponding to the segmented sections, and specifying one of the SPIDs allocated for initial transmission of the sub-code; calculating a number of remaining symbols represented by N-Fs, where N is a length of the QCTC and Fs is a starting symbol position of the sub-code of the QCTC; determining a last symbol position Ls of the sub-code by comparing the number of the remaining symbols with a length of the sub-code; and sequentially transmitting symbols of the sub-code from the starting symbol position Fs to the last symbol position Ls.

1. Field of the Invention
The present invention relates generally to code generation in a data communications system, and in particular, to an apparatus and method for generating complementary turbo codes, considering the characteristics of turbo codes in a packet communications system or a general communications system that employs a retransmission scheme.
2. Description of the Related Art
In general, an ARQ (Automatic Repeat Request) system using IR (Incremental Redundancy) is classified into an HARQ (Hybrid Automatic Repeat Request) Type II system and an HARQ Type III system. The HARQ Type II system supports a code rate R higher than 1.0 at each transmission, and variably controls an amount of transmission redundancy according to a channel condition. Here, that the code rate R is higher than 1.0 means that the number of codeword symbols is less than the number of information symbols. The HARQ Type II system combines previously received redundancy with currently received redundancy to create a new low code rate codeword, and repeats this process. However, the HARQ Type III system is designed such that a code rate R of a code used at each transmission or retransmission is less than 1.0. This is to make it possible to perform decoding with only the newly received codes when many packets are missing during transmission due to a bad channel condition or detection error. When all of the codes received at code rate R can be independently decoded, the codes are referred to as "self decodable codes" (SDCs).
The HARQ Type II or HARQ Type III system using turbo codes uses quasi-complementary turbo codes (QCTCs) in order to maximize performance of code combining. FIG. 1 illustrates a block diagram of an apparatus for generating QCTCs. The QCTCs are fully described in U.S. Pat. No. 6,877,130, granted on Apr. 5, 2005 to the same assignee herein, the contents of which are hereby incorporated by reference.
Referring to FIG. 1, an encoder 301 generates coded symbols by encoding input encoder packet. The encoder 301 uses a mother code with R=1/5 or with any other code rate. A mother code is determined by the system in use. A turbo code with R=1/5 is used herein as a mother code by way of example. A demultiplexer (DEMUX) 302 groups the coded symbols received from the encoder 301 into information symbols X (303), parity symbols Y0 (313), parity symbols Y1 (323), parity symbols Y0′ (333), and parity symbols Y1′ (343), and outputs the five symbol groups to corresponding sub-block interleavers 304, 314, 324, 334 and 344, respectively. The sub-block interleavers 304, 314, 324, 334 and 344 randomly permute the sequences output from the demultiplexer 302 by sub-block interleaving, and output the permuted symbols. The codeword symbols randomized by the sub-block interleaving are applied to corresponding blocks. The interleaved coded symbols X (306) output from the first interleaver 304 are applied directly to the input of a sequence (or symbol) concatenator 307. The interleaved parity symbols Y0 and Y1 from the second and third interleavers 314 and 324 are input to a first multiplexer (MUX) 305 and the interleaved coded symbols Y0′ and Y1′ from the fourth and fifth interleavers 334 and 344 are input to a second MUX 315. The first MUX 305 multiplexes the interleaved parity symbols Y0 and Y1 and feeds the output (316) to the sequence concatenator 307. The second MUX 315 multiplexes the interleaved parity symbols Y0′ and Y1′ and feeds the output (326) to the sequence concatenator 307. That is, the coded symbols received from the encoder 301 are classified into three sub-groups of the interleaved codeword symbols output from the interleaver 304, and the parity symbols Y0 and Y1 rearranged by the first MUX 305, and the parity symbols Y0′ and Y1′ rearranged by the second MUX 315. Next, sequence (or symbol) concatenator 307 generates one symbol sequence [A:B:C] by sequentially concatenating a sub-block-interleaved information symbol sequence A, and multiplexed parity symbol sequences B and C. A concatenated sequence (or symbol) repeater 308 performs symbol repetition on the symbols from the sequence concatenator 307 according to a preset rule. A symbol puncturer (or sub-code Cij generator) 309 generates sub-codes (i.e., QCTCs) by puncturing the symbols from the concatenated sequence repeater 308 according to a preset rule. An operation of the symbol puncturer 309 will be described in detail. A sub-code generating operation by the sub-code generator 309 is disclosed in Korean Patent Application No. 2001-7357, entitled "Apparatus and Method for Generating Codes in a Communication System", earlier filed by the applicant, the contents of which are incorporated herein by reference.
It is assumed that transmission of a sub-code starts at time k, a sub-code transmitted at time (k+h) is expressed as Cij(k+h), and the coded symbols of a mother code with R=1/5 in FIG. 1 are defined as Cm(0), Cm(1), . . . , Cm(N−1). The number, N, of the coded symbols is defined as N=L_INF×5 since the mother code rate is 1/5. Here, L_INF denotes the size of an interleaved sub-block, or the number of information symbols.
Step 1: Determining the Length of an Initial Sub-Code
For an initial transmission, one Ci0 of the first sub-codes C00, C10, C20 of available QCTCs is selected according to a given code rate and the length of the selected sub-code Ci0 is stored as a variable L_SC. The code rate or length L_SC of the sub-code is predetermined in the system according to channel environment including transmission channel condition and input data rate. The description is made in the context of three QCTCs shown in FIG. 3 for better understanding of the present invention, but the number of sub-codes is not limited.
Step 2: Selecting and Transmitting a Sub-code for Initial Transmission
After the length of a sub-code to be transmitted is determined, Cm(0), Cm(1), . . . , Cm(L_SC−1) coded symbols are selected among the coded symbols of the mother code. If L_SC exceeds N, Cm(0), Cm(1), . . . , Cm(L_SC−1) are transmitted P times and then Cm(0), Cm(1), . . . , Cm(q−1) are transmitted. Here, P and q are the quotient and remainder of L_SC/N, respectively, and P and q are calculated by L13 SC mod N. Then, the variable q is stored for the next transmission for use in detecting the position of the last symbol of the previous transmitted sub-code with respect to the block of interleaved symbols.
Step 3: Determining the Starting Position of a Sub-code for the Next Transmission and the Length of the Sub-code
For the next transmission, the code rate R_SC of a new sub-code to be transmitted is determined according to channel environment and the length L_SC of the sub-code is determined according to the determined code rate. The length L_SC and the code rate R_SC are in the relation ofL—SC=L—INF×(1/R—SC)  (1)An upper layer system transmits the sub-code length L_SC and the sub-code code rate R_SC to the symbol puncturer 309 for each transmission.
Step 4: Selecting and Transmitting a Sub-code for the Next Transmission
After the length L_SC of the sub-code to be transmitted is determined, Cm(q), Cm(q+1), . . . , Cm(q+L_SC−1) coded symbols are selected among the coded symbols of the mother code. In other words, as many symbols as the sub-code length are selected from the mother coded symbols starting with the symbol following the last symbol selected for the previous transmission. If q+L_SC exceeds N, N coded symbols starting with Cm(q) are selected recursively and transmitted P times and then the remaining q coded symbols are sequentially transmitted. Here, P and q are the quotient and remainder of (q+L13 SC)/N, respectively and P and q are calculated by (q+L_SC) mod N. Then, the variable q is stored for the next transmission for use in detecting the position of the last symbol of the previous transmitted sub-code with respect to the block of interleaved symbols. After the generated sub-code is transmitted, the procedure returns to Step 3.
A sub-code selection method for the QCTCs is illustrated in detail in a lower part of FIG. 1 by way of example. Referring to FIG. 1, a low rate sub-code with a code rate of 1/7 is initially transmitted in Case 1, and a high rate sub-code with a code rate of 4/7 is initially transmitted in Case 2. As seen from the Cases, a codeword having N codeword symbols is repeated P times, and the repeated codeword symbols are sequentially segmented in a proper size according to a length (or code rate) of the sub-code, at each transmission. In real implementation, a buffer is not used to store P codewords, but a single circular buffer is employed to store N codeword symbols, thereby making it possible to enable iterative transmission by continuous feedback. In addition, any reception buffer for storing received codewords and concatenating the stored codewords is available to a receiver as long as it can store N soft metrics.
As described above, the sub code Cij generator corresponding to the last step segments the coded symbols with R=1/5, rearranged according to a specific rule in the preceding steps, in an arbitrary length according to a sub-code code rate Rs=R_SC.
Here, if a starting point Fs for the segmentation is '0', segmentation methods according to respective sub-code code rates are illustrated in FIG. 2. Referring to FIGS. 1 and 2, if a length of the sub-code to be segmented according to a code rate of the corresponding sub-code is given, the QCTC generator (of FIG. 1) segments as many codeword symbols as the corresponding length in the rearranged codeword sequence with R=1/5. Here, the segmentation is divided into two different methods. A first method is to employ a variable starting point Fs. That is, an initially transmitted sub-code starts at Fs=0, and a starting point Fs of a subsequent sub-code is determined as an (Ls+1)th symbol position from the last symbol position Ls of the preceding sub-code. In other words, all of the sub-codes are segmented such that the rearranged codewords with R=1/5 are continuously concatenated in the repeated sequence. This is defined as a sequential starting point mode (SSPM). A second method is to employ a fixed starting point Fs. That is, an initially transmitted sub-code starts at Fs=0, and the following sub-codes start at a predefined starting point Fs. Therefore, not all of the sub-codes may be sequentially concatenated in the sequence where the rearranged codewords with R=1/5 are repeated, and segmented in the form that the codeword symbols can be overlapped according to the sub-code code rate. This is defined as a fixed starting point mode (FSPM).
In application of the QCTCs, the SSPM becomes an optimal scheme in terms of maximizing decoding performance, and can maximize a code combining gain even when considering the IR However, if a code rate of the sub-code is close to 1.0, there is a probability that sub-codes other than the initial sub-code will undesirably become non self-decodable codes (NSDCs). As stated before, it is assumed that both the HARQ Type II and the HAQR Type III are available in the SSPM. If a code rate of all the transmission sub-codes is less than 1.0, the HARQ Type III is employed, whereas if a code rate of a part of the sub-codes is higher than 1.0, the HARQ Type II is employed.
That the currently proposed system employs the HARQ Type III in which a code rate of all of the sub-codes is less than 1.0 means that a receiver performs decoding by sequentially code combining all of the received sub-codes. Further, in the SSPM, a redundancy version (RV) is not exchanged between the transmitter and the receiver. This is because it is not necessary to exchange the redundancy version RV between the transmitter and the receiver in the SSPM.
However, when some sub-codes are missing in a very poor channel environment, a phenomenon of awaiting the missing sub-codes may occur in order to continuously perform code combining. In this case, therefore, self-decodable codes (SDCs) capable of independently decoding the respective sub-codes are required as in the HARQ Type III where the RV is provided. This means that an independent RV is transmitted at each sub-code transmission. In this context, the proposed scheme is the FSPM. In this case, a conventionally used 2-bit SPID (sub-packet identification) is used together with an RV indicator, and therefore, it is possible to independently transmit 4 kinds of RVs or starting points (Fs) at each sub-code transmission. Meanwhile, the FSPM cannot become an optimal scheme in terms of maximizing decoding performance, since symbol overlapping occurs. Further, the FSPM cannot maximize a code combining gain even when considering the IR.
Therefore, in the following description of the present invention, a difference between the SSPM and the FSPM will first be analyzed, and then advantages and disadvantages of the respective schemes will be analyzed. Thereafter, it will be proven that the SSPM is superior to the FSPM. Accordingly, the present invention will provide a method of enabling the FSPM to have the same performance as that of the SSPM. In particular, the present invention will show that the FSPM has a performance degradation problem due to the symbol overlapping and the symbol puncturing, and provide adaptive SPID selection schemes as a solution to the problem.

Apparatus and method for generating codes in a communication system


An information processing device includes one or more hardware processors. The hardware processors acquire a causal relationship included in a target document that is a specific document from causal relationship management information in which one or a plurality of causal relationships are registered, which are extracted from one or a plurality of documents and each which includes a set of a first element and a second element having a relationship; acquire a similar expression of the causal relationship included in the target document based on feature management information in which features of a plurality of words included in one or a plurality of documents are registered; and acquire a generalized expression of the causal relationship included in the target document based on the causal relationship included in the target document and the similar expression.

There is known a system for searching for a document including a search character string or a similar character string similar to the search character string from a plurality of documents. For example, a sentence including important words written in a previously created important word dictionary is extracted from sentences to be searched, and the extracted sentence is converted using a generalized dictionary. Then, phrases having a causal relationship included in the converted sentence are extracted, and a causal relationship network in which the phrases are connected is generated. Then, there is disclosed a system for searching for a case similar to an input text by matching a causal relationship included in the input text and a causal network.
However, conventionally, in order to obtain a causal relationship of a generalized expression, it is necessary to prepare an important word dictionary and a generalized dictionary in advance, and the maintenance of the dictionaries is necessary. In addition, in order to obtain a generalized expression of the causal relationship included in a plurality of documents in different categories, it is necessary to perform conversion in consideration of the meaning of the causal relationship, not simple conversion. Therefore, in the conventional technology, it may be difficult to improve a conversion efficiency of the causal relationship included in a target document into the generalized expression.

Information processing device, information processing system, and computer program product for converting a causal relationship into a generalized expression


Techniques for scheduling processing tasks in a device having multiple computing elements are disclosed. A network interface controller of the device receives processing tasks, for execution on the computing elements, from a network that is external to the device. The network interface controller schedules the tasks for execution on the computing devices based on policy data available to the network interface controller. A scheduler within the network interface controller, which can be implemented as a standalone processing unit (such as a microcontroller, a programmable processing core, or an application specific integrated circuit), performs such scheduling, thereby freeing the central processing unit of the device from the burden of performing scheduling operations. The scheduler schedules the tasks according to any technically feasible scheduling technique.

A distributed computing system is a system in which multiple computing devices cooperate to perform computational work. Computing devices in such a system transmit requests to perform specific items of computational work to other computing devices in the system. Upon receiving an item of computational work, a computing device executes the work and may return result data to the computing device that sent the request to perform the unit of computational work. Efficient operation of the various computing devices in a distributed computing system is desirable.

Network interface controller-based scheduling of processing tasks in a distributed computing system


A gear pump has a toothed driving wheel, a toothed driven wheel, a front flange from which a projecting portion of the shaft protrudes, being connected to the shaft of the driving wheel, a back lid fixed to the case, and an intermediate flange between the case and the front flange. The intermediate flange has first and second chambers connected by a connection duct to the inlet or outlet fluid duct of the pump. A compensating ring is mounted in the first chamber and inserted on the shaft of the driving wheel to compensate the axial forces of the driving wheel and transmit the motion on the shaft of the driving wheel. A piston is mounted in the second chamber in order to stop against one end of the shaft of the driven wheel, in such manner to compensate the axial forces imposed on the toothed driven wheel.

1. Field of the Invention
The present invention relates to gear pumps and hydraulic gear motors, in particular to a hydraulic system used to balance the axial thrusts in pumps and hydraulic motors with external gears of bi-directional type or multiple stages, wherein helical gears are provided.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
Although specific reference is made to gear pumps hereinafter, the present invention also relates to hydraulic gear motors. Gear motors have the same construction as gear pumps, although they differ in the operating principle: whereas pumps are used to convert mechanical energy (torque applied to the drive shaft) into hydraulic energy (pressurized oil), motors are used to convert hydraulic energy (pressurized oil) into mechanical energy. The pressurized oil that is conveyed inside the hydraulic motor through one of the ports provided on the motor body acts on the toothed wheels by driving them into rotation; the torque is the output available at the shaft whereon a load is applied.
External gear pumps are commonly used in numerous industrial sectors, such as the automotive, earthworks, automation and control industries.
As shown in FIGS. 1 and 1A, a gear pump generally comprises two mutually engaged toothed wheels (1, 2). The toothed wheels (1, 2) are disposed inside a case (3) in such a way to define an inlet fluid area and an outlet fluid area.
One of the toothed wheels, which is defined as driving wheel (1), receives motion from a drive shaft, whereas the other toothed wheel, which is defined as driven wheel (2), receives motion from the driving wheel (1) it engages with. The toothed wheels (1, 2) are joined to respective shafts (10, 20) revolvingly supported by supports or bushes (4, 5).
In this description the term "front" refers to the side of the pump from which the shaft of the driving wheel protrudes, i.e. the inlet shaft that receives the rotation.
The pump comprises a front bush (4) that revolvingly supports a front portion of the shafts of the toothed wheels and a rear bush (5) that revolvingly supports a rear portion of the shafts of the toothed wheels. Each bush is provided with two circular housings that revolvingly support a portion of the shafts of the two toothed wheels.
A front flange (6) and a back lid (7) are fixed to the case (3) in such way to close the bushes (4, 5) and the toothed wheels (1, 2) inside a box composed of the case (3), the front flange (6) and the back lid (7). The front flange (6) is provided with an opening from which the shaft (10) of the driving wheel (1) comes out. Therefore a projecting portion (13) of the shaft of the driving wheel frontally protrudes from the front flange (6) in order to be connected to a drive shaft that transmits motion.
Gear pumps are volumetric machines because the volume comprised between the compartments of the teeth of the two toothed wheels and the external case is transferred from the inlet area to the outlet area by means of the rotation of the toothed wheels. Different types of fluid can be used, as well as different outlet and/or inlet pressure and pump displacement values.
The fluid used in the most typical application is oil, which is partially incompressible. Reference pressure values are typically the ambient pressure for the inlet pressure, whereas the outlet pressure reaches maximum values of 300 bar.
As shown in the example of FIGS. 1 and 1A, the toothed wheels (1, 2) have a straight external toothing, the same dimensions and a unitary transmission ratio.
Referring to FIG. 2, if toothed wheels with straight toothing are used, during operation the toothed wheels transmit a transmission force (F) that can be decomposed into a radial transmission force component (Fr) (shown in FIG. 2) directed in radial direction with respect to the axis of rotation of the toothed wheels and a transverse transmission force component (Ft) (not shown in FIG. 2) directed in radial direction with respect to the axis of rotation of the toothed wheels.
Referring to FIG. 2A, in these conditions, a pressure force (P) is generated in the inlet area (shown in bold in the left-hand side of FIG. 2A), which acts on the surfaces of the toothed wheels. The resultant of the pressure force (P) can be likewise decomposed in two components: a radial pressure force component (Pr) and a transverse pressure force component (Pt). In such a case, no force in axial direction is exerted on the toothed wheels.
The use of helical gears, when configured as disclosed in the international patent application PCT/EP2009/066127 or in the U.S. Pat. No. 2,159,744 or U.S. Pat. No. 3,164,099, allows for considerably reducing the noise and pulses induced by the pump in the hydraulic circuit.
It must be noted that in order to correctly engage two helical toothed wheels with the same geometrical features, the inclination of the helix must have a discordant direction.
FIGS. 3A, 3B, 3C and 3D disclose a gear pump with a driving wheel (1) and a driven wheel (2) with helical toothing. The use of toothed wheels with helical toothing generates axial loads or stress (Fa, Pa) during operation. The higher the helix angle ?b of the helical toothing is, the higher said axial loads or stress (Fa, Pa) will be (FIGS. 3A, 3B). The generation of the axial stress (Fa, Pa) is caused by the projection of the transmission forces (Fa) and the pressure forces (Pa) acting on the sections of the toothed wheels along the axial direction.
FIG. 3D shows the resultants (A, B) of all axial forces acting on the toothed wheels (1, 2), respectively.
If not opposed, the generation of the axial stress (A, B) considerably increases the specific pressure that is discharged on the bushes (4, 5), thus reducing both the mechanical efficiency because of losses by friction and the reliability and maximum pressure of the pump.
The problem of balancing the axial loads can be solved in different ways.
Referring to FIG. 4, the use of bi-helical gears is known to solve the problem of balancing the axial loads, because the axial forces (A, B) are directly balanced on the toothed wheels. Such a solution is impaired by several drawbacks: in fact, the higher constructional complexity of the bi-helical toothed wheels, together with the higher accuracy required during the construction of the high-pressure gear pumps or motors, makes such a solution cost ineffective.
An alternative method used to balance the axial forces is disclosed in the U.S. Pat. No. 3,658,452, wherein a right-hand pump (i.e. a pump with driving shaft with clockwise rotating right-hand helix) and driven shaft with left-hand helix are used.
Referring to FIG. 5 (which corresponds to FIG. 1 of U.S. Pat. No. 3,658,452) the axial forces (A, B) acting on the driving and driven toothed wheels (11, 12) of the pump are both directed towards the back lid (16) and opposed by hydraulic pistons (51, 52) disposed at the ends of the toothed wheels, which exert contrast forces (A′, B′). The hydraulic pistons (51, 52) are fed by means of passages (59, 60, 61) that connect the rear chambers (57 and 58) of the hydraulic pistons with the inlet area of the pump. The area of the hydraulic pistons (51, 52) must be suitably dimensioned in order to balance the axial forces (A, B).
The axial forces (A, B) acting on the toothed wheels are generated by the contribution of two factors: the axial component of the pressure (Pa) (FIG. 3B) and the axial component of the force (Fa) generated by the torque transmission from the driving wheel to the driven wheel (FIG. 3A). Regardless of the direction of rotation and the direction of the helix used for the wheels, the forces (Pa and Fa) are always concordant on the driving wheel, whereas the forces (Pa and Fa) are always discordant on the driven wheel.A=Pa+Fa[N]  (1)B=Pa−Fa[N]  (2)
If a pump with helical gears according to the prior art in right-hand rotation (clockwise-rotating driving shaft) is considered and a driving shaft with right-hand helix is used (FIG. 5), at a known running speed, the absorbed torque at the driving shaft is:
                    Mt        =                                            V              ·              P                                      20              ·              π              ·                              η                m                                                                    [            Nm            ]                                              (        3        )
V=Displacement [cm3/rev]
P=Pressure difference between inlet and outlet [bar]
nm=Hydro-mechanical output (experimentally obtainable value)
Assuming that half of the torque is transferred to the fluid by the driving wheel during its pumping action, the torque transmitted to the driven wheel Mtcto is half of the total torque.
                              Mt          CTO                =                              Mt            2                                          [            Nm            ]                                              (        4        )
The axial transmission force Fa generated by the helical toothed wheels is:
                    Fa        =                                                            1000                ·                                  Mt                  CTO                                                            Dp                2                                      ·                          Tan                                            (                β                )                                              =                                                    50                ·                V                ·                P                                            π                ·                Dp                ·                                  η                  m                                                      ·                                          Tan                                                  (                  β                  )                                                                          [                N                ]                                                                        (        5        )
Dp=Operating pitch diameter of toothed wheels [mm]
β=Inclination angle of helix [°]
Because of the known action and reaction principle, the force Fa acts on the driving and driven wheel with the same intensity, but with opposite direction.
The axial force generated by the pressure Pa is the resultant of the pressure along the axial direction:
                    Pa        =                                            h              ·              l              ·              P              ·                              Tan                                                  (                  β                  )                                                      10                                          [            N            ]                                              (        6        )
h=Tooth height [mm]
l=Ring width [mm]
In view of the above, the force Pa has the same intensity and the same direction on both toothed wheels. According to the most typical dimensioning of the toothed wheels, Pa>Fa and consequently the forces F1 and F2 always have a concordant direction.
The diameters ΦA and ΦB of the compensating pistons are obtained from the formulas (7) and (8):
                              Φ          A                =                  2          ·                                                                      10                  ·                  A                                                  π                  ·                  P                                                                                [              mm              ]                                                          (        7        )                                          Φ          B                =                  2          ·                                                                      10                  ·                  B                                                  π                  ·                  P                                                                                [              mm              ]                                                          (        8        )
Both forces Fa and Pa linearly depend on the value of the inlet pressure P (see formulas (5) (6)). Consequently, after calculating the diameter of the compensating pistons, the axial forces are completely balanced at any value of the pressure P.
The use of the compensating pistons is a rather inexpensive and easy-to-make solution because the work operations and the parts are simple and reliable. The precepts disclosed by the U.S. Pat. No. 3,658,452 can solve the problem of balancing the axial forces only in case of monodirectional motors, in which the resultant forces A and B must be always directed towards the back lid (see FIG. 5), (i.e. in case of a right-hand pump with right-hand driving gear and left-hand driven gear, or in case of a left-hand pump with left-hand driving gear and right-hand driven gear).
However, some hydraulically controlled applications require the use of bi-directional or multiple stage hydraulic pumps or gears.
The use of bidirectional pumps (with two flow directions) allows for inverting the rotation of the driving shaft, thus inverting the direction of the oil flow and the high and low pressure areas, inverting, for instance, the motion of hydraulic actuators. Likewise, the use of bidirectional motors is useful in the applications that require inverting the direction of the torque available at the outlet shaft of the hydraulic motor.
FIG. 6A shows the distribution of the axial forces in case of a bidirectional pump, in an operating condition in which the axial forces A and B are directed towards the front flange. In such a case, the solution disclosed in U.S. Pat. No. 3,658,452 is not applicable because the inversion of the motion and of the inlet side with the outlet side results in the inversion of the axial forces (A, B) acting on the toothed wheels (1, 2), as shown in FIG. 6B. In such a case the axial forces (A, B) are directed towards the front flange (6) and not towards the back lid (7). Because of the inevitable projecting portion (13) of the shaft of the driving wheel (1) that protrudes from the front flange (6), the axial force (A) on the driving wheel (1) can no longer be balanced by means of a hydraulic piston, like in the solution shown in FIG. 5.
The same situation is found in a hydraulic motor with a high-pressure fluid inlet side and a low-pressure fluid outlet side. In such a case, there are no driving wheel and driven wheel, but simply a first toothed wheel (1) and a second toothed wheel (2). Moreover, the projecting portion of the shaft (13) is adapted to be connected to a load, not to a motor.
FIG. 7 shows a multiple two-stage pump comprising a front stage (SA) and a rear stage (SB). For the sake of clarity, FIG. 7 shows a two-stage pump, but the solution can be applied also to a higher number of stages. A multiple pump is necessary to connect multiple independent circuits to a single power take-off. In such a case the pumps are connected in parallel and the rear stage (SB) receives the necessary torque by means of a mechanical connection (500) (such as Oldham coupling or splined coupling), from the shaft of the driving wheel of the front stage (SA). Also in the case of multiple pumps, the solution disclosed in the U.S. Pat. No. 3,658,452 is not applicable because an end portion (T) of the shaft of one of the toothed wheels of the front stage (SA) is engaged to transmit the motion to the rear stage (SB). In fact, the front stage (SA) cannot be provided with a closed back lid because the end portion (T) of the shaft of a toothed wheel must protrude in the back to transmit the motion to the rear stage (SB).
In general, the precepts disclosed by the U.S. Pat. No. 3,658,452 are not applicable when the axial forces (A, B) are directed towards a side of the pump that is crossed by the shaft of a toothed wheel.
The purpose of the present invention is to remedy the drawbacks of the prior art, by providing a hydraulic system to balance the axial forces in gear pumps or hydraulic motors with helical toothing of bidirectional or multiple stage type.

Gear pump or hydraulic gear motor with helical toothing provided with hydraulic system for axial thrust balance


A pixel array including first and second signal lines, an active device, a pixel electrode and selection lines is provided. The second signal lines are intersected with the first signal lines to drive the active device, and the pixel electrode is connected to the active device. The selection lines are electrically insulated to the second signal lines and intersected with the first signal lines, where at least one selective line is disposed between the adjacent two second signal lines. An amount ratio of the first signal lines and the selection lines is a1/a2, where a1≦a2, and when a1 and a2 are mutually prime numbers, the selection lines are divided into a plurality of groups, and each group includes a1 selection lines electrically connected to the first signal lines, and (a2−a1) selection lines not electrically connected to the first signal lines.

Technical Field
The invention relates to a pixel array. Particularly, the invention relates to a pixel array adapted to a slim border design.
Related Art
In recent years, along with development of technology industry, electronic apparatuses such as mobile phones, tablet computers or ebooks have been widely applied in people's daily life. As the electronic apparatuses are more and more popularised and developed towards a trend of convenience and multifunction, when consumers select and purchase the electronic apparatuses, a display device with a slim border becomes a main consideration factor in purchase besides software and hardware functions of the electronic apparatus.
Generally, as a screen is developed towards a trend of lightweight and a profile thereof is developed to have a maximum display region, a non-display region used for shielding connection lines at periphery of the screen is reduced to enlarge the display region of the screen, so as to cope with the design requirement of slim border. As shown in FIG. 1, a method for narrowing a frame border is developed in recent years, by which selection lines 10 are configured besides scan lines 30 and data lines 40, where the selection lines 10 are electrically connected to the corresponding scan lines 30 through bridge points X. In this way, a chip 20 can transmit scan signals to the corresponding scan lines 30 through the selection lines 10. According to such layout design, since both of the scan lines 30 and the data lines 40 are wired to the chip 20 from a same side of the display region, a width W of the non-display region along a horizontal direction is narrowed, so as to cope with the design requirement of slim border. However, along with increase of resolution, a signal coupling effect of the selection lines 10 becomes more obvious. When the selection lines 10 transmit signals, voltages of pixels located beside the selection lines 10 are liable to be influenced to cause a gray level difference between a region A1 with relatively denser bridge points X and a region A2 with relatively sparser bridge points X, so that display quality is influenced.


A photonic bandgap fiber includes a core and a cladding that surrounds the core. In this photonic bandgap fiber, high refractive index portions which have a refractive index higher than that of a medium of the cladding are provided in the cladding so as to form a triangular lattice structure with a lattice constant Λ, and the refractive index of the core is higher than the refractive index of the medium of the cladding and lower than the refractive index of the high refractive index portion. The coupling length between the core and the high refractive index portion that is closest to the core is longer than the coupling length between adjacent high refractive index portions, or a periodic structure formed by the high refractive index portions is not provided around the entirely of the area along the circumference of the core.

In recent years, high-power optical amplifiers (fiber lasers, fiber amplifiers) using a rare-earth doped optical fiber have received attention. Among these, since high-power fiber lasers have the characteristics of being easily cooled and offering high beam quality compared to solid-state lasers, they are attracting a great amount of attention particularly in the field of laser machining. In a high-power fiber laser, a pumping light and a signal light propagate through a fiber, and the signal light is amplified by a stimulated emission process due to the population inversion of rare-earth ions that are pumped by the pumping light. This high-power fiber laser has an amplifying fiber that amplifies the signal light and a light-guiding fiber that guides the amplified signal light to a predetermined place. However, as the output power of fiber lasers has increased, two problems have become evident.
The first problem is stimulated Raman scattering. When stimulated Raman scattering occurs, a part of the output of the signal light is converted into a light (a Stokes light) having a longer wavelength, thus the output power of the signal light falls. This is a problem in both the amplifying fiber and the light-guiding fiber.
One more problem is the amplified spontaneous emission. In the amplifying fiber, in addition to the stimulated emission that amplifies the signal light, spontaneous emission is generated from the rare-earth ions. When this spontaneous emission propagates through the fiber together with the signal light, the spontaneous emission is amplified by the pumping light, leading to a drop in the pumping light that is used for amplification of the signal light, and as a result the output power of the signal light decreases. This is a problem in the amplifying fiber.
In order to rectify these problems, two measures have been proposed. The first measure uses a fiber whose cut-off wavelength of the fundamental mode exists at a wavelength that is longer than the wavelength of the signal light. Thereby, it is possible to suppress propagation of light of longer wavelengths than the signal light, suppress propagation of Raman scattering light and light on the longer wavelength side, and reduce stimulated Raman scattering light and amplified spontaneous emission at longer wavelengths (see "Suppression of Raman Gain in Single-Transverse-Mode Dual-Hole Assisted Fiber," Optics Express, 13, pp. 8921, 2005). The other measure is a method that involves disposing a ring around a core so as to couple Raman scattering light and spontaneous emission that are guided through the core to a mode that is guided through the ring and cause radiation (see "Suppression of Stimulated Raman Scattering in a Cladding Pumped Amplifier with an Yb-Doped Fiber," CLEO2006).
However, there are the following problems in the conventional art.
In the fiber that is disclosed in the Suppression of Raman Gain publication, since the cut-off wavelength of the fundamental mode exists at a wavelength that is longer than the wavelength of the signal light, it is not possible to suppress spontaneous emission on the shorter wavelength side than the wavelength of the signal light.
In the fiber that is disclosed in the Suppression of Stimulated Raman Scattering publication, since the coupling to the mode guided through the ring exists at many wavelengths, even the signal light may be suppressed due to manufacturing variations, so that manufacturing is difficult or the tolerance with respect to manufacturing variations is low. Also, since the coupling to the mode that is guided through the ring exists at a comparatively narrow band of approximately 10 nm to 30 nm, it is difficult to accurately match the band to the wavelengths that need to be suppressed in terms of manufacturing, and a band of Raman scattering cannot be entirely covered, and suppression of the spontaneous emission can only be performed in a restricted band.
Exemplary embodiments of the present invention were devised in view of the above circumstances and have an objective to provide an optical fiber that is capable of effectively suppressing propagation of light on either shorter wavelengths or longer wavelengths other than the signal light, and that can be manufactured so that there is no suppression within the wavelength of the signal light without a wavelength in the propagation region at which loss increases rapidly.


A sowing heart monitoring apparatus for connection to a sowing heart and for monitoring of the sowing heart with a line camera with one detection direction, a housing which can be attached to the sowing heart for accommodating the line camera and a radiation source for generating electromagnetic waves which can be detected by the line camera with one radiation direction. The sowing heart monitoring apparatus is made such that electromagnetic waves which have been generated by the radiation source can be detected by the line camera after reflection on one reflection surface of a rotating sowing disc of the sowing heart and can be evaluated by an evaluation unit. The invention also relates to a sowing heart and a single-seed drill.

Monitoring apparatus for monitoring the operation of single-seed drills are known in different versions. Often the monitoring is carried out on a conveying channel due to easy accessibility, as for example in document WO 2005/096799 A1 or WO 2005/096798 A1.
Monitoring apparatus are used among others for control and adjustment as well as checking of the proper operation of the sowing sets. There is a requirement that the monitoring responds quickly and works easily and without problems. Furthermore the monitoring apparatus should work as economically and maintenance-free as possible.

Sowing heart monitoring apparatus, sowing heart and single-seed drill


The present invention relates to methods and kits useful in the diagnosis of a pancreatic-based fat malabsorption disorder in a mammal.

Cystic Fibrosis (CF) is the most common life-shortening autosomal recessive condition in the Caucasian population, with an estimated 25,000 people affected and seven million carriers in the U.S. alone.
Over the last 29 years, the median age of survival of people having CF has increased dramatically from 14 years in 1969 to 31 years of age in 1997. CF is therefore now both a pediatric and adult disease. Growth and nutritional status in people having CF are related to the severity of lung disease, the severity of pancreatic insufficiency, and to nutrient intake and absorption.
Considering national data (CFF Patient Registry), nutrition-related growth failure is still at an unacceptably high rate. In 1997, 19% of patients having CF were below the 5th percentile for height, and 24% were below the 5th percentile for weight. If the 10th percentile for weight is considered the more appropriate screen for patients with a nutritionally high-risk condition such as CF, then 33% of the patients with CF were below the desirable level in 1997. Except in the end stage of the lung disease, most of this growth failure and poor nutritional status (reduced weight for height) is associated with pancreatic insufficiency.
Improved treatment of pancreatic insufficiency in CF patients, as well as in other patients suffering from non-CF related malabsorption, requires an efficient clinical care test for malabsorption of nutrients through the intestinal wall. New pancreatic enzyme products or modifications of current products require evaluation in a research quality test for malabsorption. Given the occurrence of the previously unrecognized diagnosis of fibrosing colonopathy, accurate documentation of the severity of malabsorption is even more important to the CF care community and to patients having CF and pancreatic insufficiency (Smyth R. L., et al., 1995; Lancet, 346(8985):1247-51; Lloyd-Still, J. D., et al., 1998; J. Pediatr Gastroenterol Nutr., 26(5):489-95).
The important link between pancreatic insufficiency and malnutrition in children with CF was established over 40 years ago (Pencharz, P. B. et al., 1993; Annu. Rev. Nutr. 13:111-36). These investigators demonstrated that pancreatic enzymes improved fat absorption and led to positive nitrogen balance in the patient. Steatorrhea and malabsorption are the presenting symptoms in more than 20% of infants and children with CF. More than 85% of individuals with CF have pancreatic insufficiency and require exogenously added pancreatic enzymes in their diet (FitzSimmons, S. C., 1993; J. Pediatr., 122:1-9). Assessing the degree of fat malabsorption in the intestine is helpful for guiding both enzyme therapy and nutritional intervention in children and adults having CF and pancreatic insufficiency.
The are a variety of other pathological conditions that are associated with aberrant fat absorption. These include, without limitation, hereditary pancreatitis, α1 anti-trypsin deficiency, Shwachman Syndrome, Johanson-Blizzard Syndrome, sideroblastic anemia, pancreatic insufficiency, lipase deficiency, co-lipase deficiency in children, both partial and complete pancreatic surgical resection, pancreatic cancer, chronic and autoimmune pancreatitis, hyperlipidemia, and hyperparathyroidism. Improved methods for assessing aberrant pancreatic-based fat malabsorption in each of these disorders should facilitate diagnosis and the development of disease management regimens.
The 72-hour stool and diet collection method is considered the standard test for measuring the degree of fat malabsorption in a patient (Van De Kamer, J. H. et al., 1949; J. Biol Chem. 177:345-55; Jeejeebhoy, K. N. et al., 1970; Clin. Biochem. 3:157-63). A coefficient of fat absorption (CFA) obtained from the 72-hour stool collection and dietary intake method is widely accepted as a clinical, diagnostic, but non-specific, test for assessing fat malabsorption. The accuracy of this test is dependent on at least three days of entire stool collections together with consumption and documentation of a defined moderate to high fat diet. Despite its chemical accuracy, this test is prone to errors due to inadequate documentation of dietary intake, incomplete stool collections and day-to-day variation in fecal fat excretion (Holmes, G. K. T., 1988; BMJ, 296:1552). The technical and aesthetic difficulties associated with stool collection, storage and analysis make this test very unappealing to patients, families and lab workers. Few local laboratories conduct quantitative fecal fat analyses, thereby requiring additional time and expense for stools to be shipped to regional labs. The lag period between sample collection and reported results further fuels the disinterest in this test. Therefore, despite the clinically important data provided by the 72-hour stool and dietary collection method, this test is under-utilized or avoided in most clinical care and research settings. Even with the availability of capable labs, this potentially important clinical test is poorly accepted and under-utilized by both patients and care providers (Holmes, G. K. T., 1988; BMJ, 296:1552) thus contributing to the malnutrition and growth failure associated with CF.
Several alternative tests have been developed for assessing fat malabsorption, but all have significant limitations and have failed to gain wide acceptance as accurate or practical alternatives to the 72-hour stool and diet collection method. Several of these tests are discussed below.
The Spot Sudan III stain test is a qualitative test which involves the microscopic examination of a random fecal specimen stained with the Sudan dye (Drummey, G. D., et al., 1961; N. Engl. J. Med., 264:85-7). Even when objective criteria are used, the results are poorly reproducible in the ranges of mild to moderate steatorrhea common in patients with CF. The accuracy of this test is increased when homogenized pooled stool samples are used. However, from the patient's and family's perspective, this renders the test no different from the 72-hour stool collection method.
The Acid Steatocrit test utilizes a small (about 5 grams) stool specimen which is spun to separate the acidified fat from the solid stool (Tran, M., et al., 1994; J. Pediatr. Gastroenterol Nutr., 19:299-303; Phuapradit P., et al., 1981; Arch. Dis. Child., 56:725-7). Correlation with the 72-hour stool and diet collection method only occurs when homogenized-pooled stool is used. Therefore, requirement for a pooled stool collection offers no added benefit to the patient and family, and is not well correlated with the 72-hour collection method.
Breath tests, such as 14C and 13C Triolein breath tests (Newcomer, A. D., et al., 1979; Gastroenterology, 76:6-13; Watkins, J. B., et al., 1982; Gastroenterology, 82:911-7), are non-invasive tests utilizing small amounts of dietary fat labeled with stable or radioactive isotopes. Fat malabsorption is predicted by the labeled CO2, and is an indicator of the absorbed dietary fat. The data may be used to qualitatively monitor response to pancreatic enzyme therapy in cases of known pancreatic insufficiency (Amarri, S., et al., 1997; Arch. Dis. Child., 76:349-51; Goff, J. S., 1982; Gastroenterology, 83:44-46). When compared with 72-hour stool and diet collection method, breath tests had up to 80% sensitivity but only 45% specificity (Pedersen, N. T., et al., 1991; Scand. J. Clin. Lab. Invest. 51:699-703). In using the breath test, there is also the assumption that the subject's pulmonary status is normal or near normal, which is not always the case in patients having CF. Also, 14C is a radioactive compound, and therefore not suitable for use in children. 13C, the stable isotope, is safe for use in children, however, costs of the substrate and equipment required for analysis (mass spectrometry) are very high.
Retinyl palmitate, a long chain fat which is hydrolyzed by lipase prior to intestinal absorption via the chylomicron route, has successfully been used as marker for monitoring postprandial chylomicron response to dietary fat. However, the specificity of retinyl palmitate for assessing fat malabsorption due to pancreatic insufficiency in humans is limited because there are intrinsic gut brush border lipase enzymes which specifically hydrolyze retinyl esters (Rigtrup, K. M., et al., 1994; Am. J. Clin. Nutr., 60:111-116). In addition, specific defects involving the intestinal handling of retinol may occur in CF and other pancreatic-fat based malabsorption disorders, further limiting the use of this assay to monitor dietary fat malabsorption caused by pancreatic insufficiency (Ahmed, F., et al., 1990; Arch. Dis. Child., 65(6):589-593).
Apolipoprotein A-IV (A-4) is a 46-kD lipoprotein exclusively synthesized with chylomicrons in the enterocyte in response to dietary fat in humans (Green, P. H. R., et al., 1982; Gastroenterology, 83:1223-30). The rate of synthesis and secretion of this compound correlates with the consumption of dietary long chain triglycerides in a dose dependent pattern (Rodriguez, M-D., et al., 1997; Am. J. Physiol., 272:R1170-177). Since A-4 is rapidly catabolized, serum levels of this compound are dependent on rate of synthesis of A-4, and therefore A-4 may be used as a marker of absorbed dietary fat (Rader, D. J., et al., 1993; J. Clin. Invest., 92:1009-17). However, the immunoassays used for the detection of A-4 are not well standardized, thereby limiting broad, clinical utility.
The Pentadecanoic Acid (IPPA) test is a non-invasive qualitative test in adults used to evaluate pancreatic lipase activity. The assay involves oral administration of a radiolabeled triglyceride containing iodophenylpentadecanoic acid, 123I-IPPA, as a long chain fatty acid linked to position-3 of the glycerol backbone. Hydrolysis of the triglyceride by pancreatic lipase is required before IPPA is absorbed. After absorption, IPPA is metabolized by β-oxidation and the final metabolic product, 123I-p-iodobenzoic acid, is excreted in urine. Scintigraphic analysis of urine for 123I-p-iodobenzoic acid provides qualitative data about the activity of pancreatic lipase. However, the involvement of radioactivity limits broad applicability of this test to children.
Other tests which analyze stool for fat and energy content have been developed, including fecal bomb calorimetry and near infrared fecal spectroscopy (Benini, L., et al., 1989; Gut., 30:1344-7; Emmanuel, B., 1974; Biochem. Biophys. Acta., 337:404-13). In all cases, correlation with the 72-hour stool and diet collection method only occurs when pooled homogenized fecal samples are used. Therefore, these tests provide no added benefit to the patient and family than those described above.
All of the prior art assays have failed to become widely accepted in CF research or clinical care of patients with pancreatic fat-based malabsorption disorders. Thus, there remains a need in the art for improvements in methods for the diagnosis and nutritional care of patients with CF and other pancreatic insufficiency-related pathologies.

Methods and kits for diagnosing a pancreatic-based fat malabsorption disorder


The invention relates to a compound of Formula I or IA and methods of treating cystic fibrosis comprising the step of administering a therapeutically effective amount of a compound of Formula I or IA to a patient in need thereof:

Cystic fibrosis (CF) is a lethal, recessive, genetic disease affecting approximately 1 in 2500 live births among Caucasians. (Cohen-Cymberknoh, M. et al., Am. J. Respir. Crit. Care Med. 1463-1471, 2011; Boat et al., The Metabolic Basis of Inherited Disease, 6th ed., pp 2649-2680, McGraw Hill, NY (1989)). Approximately 1 in 25 persons are carriers of the disease. The major symptoms of cystic fibrosis include chronic pulmonary disease, pancreatic exocrine insufficiency, and elevated sweat electrolyte levels. The symptoms are consistent with cystic fibrosis being an exocrine disorder. (Hantash, F: U.S. Patent Application No. 20060057593). The CF gene codes for a cAMP/PKA-dependent, ATP-requiring, membrane chloride ion channel, generally found in the apical membranes of many secreting epithelia and is known as CFTR (cystic fibrosis transmembrane conductance regulator). There are currently over 1900 known mutations affecting CFTR, many of which give rise to a disease phenotype. Around 75% of CF alleles contain the ΔF508 mutation in which a triplet codon has been lost, leading to a missing phenylalanine at position 508 in the protein. This altered protein fails to be trafficked to the correct location in the cell and is generally destroyed by the proteasome. The small amount that does reach the correct location functions poorly. (Cuthbert A W, British Journal of Pharmacology, 163(1), 173-183, 2011).
Mutations in the CFTR gene result in absence or dysfunction of the protein that regulates ion transport across the apical membrane at the surface of certain epithelia. Although CFTR functions mainly as a chloride channel, it has many other roles, including inhibition of sodium transport through the epithelial sodium channel, regulation of the outwardly rectifying chloride channel, ATP channels, intracellular vesicle transport, and inhibition of endogenous calcium-activated chloride channels. CFTR is also involved in bicarbonate-chloride exchange. A deficiency in bicarbonate secretion leads to poor solubility and aggregation of luminal mucins. Obstruction of intrapancreatic ducts with thickened secretions causes autolysis of pancreatic tissue with replacement of the body of the pancreas with fat, leading to pancreatic insufficiency with subsequent malnutrition. In the lungs, CFTR dysfunction leads to airway surface liquid (ASL) depletion and thickened and viscous mucus that adheres to airway surfaces. The result is decreased mucociliary clearance (MCC) and impaired host defenses. Dehydrated, thickened secretions lead to endobronchial infection with a limited spectrum of distinctive bacteria, mainly Staphylococcus aureus and Pseudomonas aeruginosa, and an exaggerated inflammatory response leading to development of bronchiectasis and progressive obstructive airways disease. Pulmonary insufficiency is responsible for most CF-related deaths. (Cohen-Cymberknoh, M et al., Am. J. Respir. Crit. Care Med. 1463-1471, 2011).
The prognosis for the treatment of CF has improved over the last 40 years. This was achieved by improving pancreatic enzyme supplements, drugs designed to treat pulmonary infection, reduce inflammation and enhance mucociliary clearance. Currently the therapeutic challenges are to correct the biochemical defect of CF and to identify effective treatments for chronic respiratory infection. (Frerichs C. et al., Expert Opin Pharmacother. 10(7), 1191-202, 2009).

Triazolopyridine compounds and methods for the treatment of cystic fibrosis


A universal joint constituted by a first joint, a second joint and a rolling element. The first joint is formed by friction-welding an outer race member and a connecting shaft member. The connecting shaft member has a ring-shaped connecting portion which is welded with a bottom portion of the outer race member. The connecting portion is formed to project from a recess portion of the connecting shaft member toward the outer race member. Therefore, burr generated by the friction welding between the connecting portion and the bottom surface of the outer race member is received in a space defined by the recess portion and the bottom surface of the outer race member. This facilitates removal of the burr.

The present invention relates to a universal joint for transferring motive force between a drive shaft and a driven shaft in equal speed.
Various universal joints for equivalently transferring drive power from a drive shaft to a driven shaft have been proposed and in practical use. A typical universal joint is constituted by a first joint, a second joint and a rolling element. The first joint includes a connecting shaft member connected to an output shaft of a reduction gear and an outer race member connected to the connecting shaft member. The second joint includes a transfer shaft interconnected with driven wheels and an inner race member connected to the transfer shaft and engaged with the outer race member through the rolling element. A popular production method of the first joint is disclosed in a Japanese Utility Model Provisional Publication No. 55-175627 in which a ring-shaped projection formed on an end surface of an outer race member is welded with a ring-shaped connecting portion of a connecting shaft member by means of friction welding. The welded portion is covered with a dust seal member to facilitate the removal of burr generated by the friction welding.
However, this joint obtained by the friction welding of two projections is required to further improve the productivity and the material efficiency without complicating the structure of the connecting shaft member.


The present invention is to provide a TV image conversion device for turning a computer on or off by means of a multimedia remote control. The TV image conversion device is electrically coupled to a computer enabling a user to operate a computer on-off switch on the multimedia remote control to turn the computer on or off wirelessly rather than walk to a computer to either turn the computer on or off by pressing an on/off switch on the computer. By utilizing this, the above drawback of incapable of turning a computer on or off by means of a remote control as experienced by the prior art can be overcome.

Users, especially employees involved in using computers, may sit in front of the computer for hours of every day. Such work can be tedious. For the purpose of entertainment a person may like to listen to news and/or music, play games, watch VCD (video compact disc) movies, or even watch TV while working or during breaks. In this regard, a person may install one or more additional peripherals (e.g., accelerator card, CD-ROM (compact disc-read only memory) driver, TV image conversion device, or the like) and their associated software in the computer. Such peripherals do not occupy precious space on a user's desk. Also, a user can run an audio-video (AV) playing software or image fetching software to play a VCD for watching movies as well as recording the same. Particularly, the TV image conversion devices such as internal TV cards or external set-top boxes available from some manufacturers have a feature of picture in picture in associated software which is sold for a fee or for free. Hence, a user can use the computer while watching a TV program. Thus, a wide variety of TV image conversion devices are produced by computer peripheral manufacturers. Further, TV image conversion devices are gaining popularity among many computer users.
Conventionally, a multimedia remote control is free when a user buys a TV card having many powerful features. Also, the user has to install multimedia software after mounting the TV card in a computer. Thereafter, the user can turn on the computer to run the software to play a VCD to watch a movie or watch TV. Also, the user can operate the multimedia remote control to select a desired channel for watching or adjusting volume. In case the user does not want to play the VCD or watch TV any more and wants to stop using the computer, the user has to stop running the multimedia software and perform the necessary shutdown step prior to turning off an on/off switch on the computer. This is in contrast to turn off of a domestic appliance, which is a simple operation involving aiming a remote control at the domestic appliance. As such, it is typical that a user has to rise to walk to a computer to either turn the computer on by pressing the on/off switch or perform the shutdown step prior to turning the computer off by pressing the on/off switch rather than operate a remote control to do the same in one operation. Hence, the above computer turning on/off procedure is not user friendly for many users who are familiar with the operation of domestic appliances.
Thus, it is desirable among TV image conversion device designers and manufactures to provide a novel TV image conversion device for fulfilling the needs of vast users.

TV image conversion device for turning computer on or off by means of multimedia remote control


The present invention discloses an apparatus (160) comprising a common mode generator circuit (162) coupled to a current directing circuit adapted to provide current to a first write head connection node (170) and to a second write head connection node (172). The common mode generator circuit (162) is adapted to provide additional current to the first write head connection node (170) and to the second write head connection node (172), wherein the first write head connection node (170) is adapted to produce a first write signal, wherein the second write head connection node (172) is adapted to produce a second write signal, wherein the current and the additional current are adapted to establish a voltage across the first write head connection node (170) and the second write head connection node (172), wherein the voltage is adapted to be pulled toward a first polarity based on the first write signal and toward a second polarity based on the second write signal, and wherein the voltage pulled toward the first polarity and the voltage pulled toward the second polarity are substantially centered about a common mode voltage.

The interconnecting leads between preamplifiers and read/write heads in hard disk drive devices are spaced very close together, often within a few mils of each other. The read sensors consist of very sensitive magnetoresistive material that cannot tolerate excessive voltages. In contrast, the write element consists of a thin-film inductor which requires large sub-nanosecond voltage swings for high data rate systems. Because of the close spacing of the writer and the reader, an asymmetrical voltage swing provided to the write head can couple into and damage the adjacent read element.
Prior art apparatuses for use in applying write signals for driving a write head to effect writing information to a memory device, such as write driver preamplifiers, are often not designed to effect symmetrical voltage swing during the write current reversal period. Write current reversal is commonly employed to differentiate between digital symbols (e.g., a "1" and a "0") in writing information to a memory device. Any voltage asymmetry in carrying out write current reversal will result in energy coupling into the adjacent reader(s), and can damage or destroy the sensitive read element(s). Read elements and write elements are commonly situated in very close proximity in read/write heads associated with storage mediums such as HDD devices.
The coupling current can be modeled by:
                    I        =                  C                                              ⅆ              V                                      ⅆ              t                                                          (        1        )                            Where, C is the average capacitance from the writer to the reader,                    dV is the asymmetrical voltage, and            dt is the net change in time.
From Eqn. (1) one can observe that the coupling current will increase when the spacing between traces is decreased ((i.e., when capacitance is increased), when the writer voltage is asymmetric (i.e., when dV is increased), or when the switching speed is increased (i.e., when dt is decreased).
Such prior art apparatuses further attempt to provide symmetrical voltage swing by biasing the common-mode write voltage about mid supply for a single write digital-to-analog converter (DAC) setting. Therefore, the writer's output common-mode will vary with the programmed write current and the writer's voltage swing will be symmetric for only one programmed setting. Further limitations of these prior art apparatuses include the difficulty in programming the mid-supply voltage which is typically only 1 bit programmable.
It is therefore desirable for the present invention to overcome the aforementioned problems and limitations associated with the prior art apparatuses that apply write signals to drive a write head for writing information to a memory device.

Hard disk drive preamplifier write driver


An embodiment relates to a light emitting device comprise a second electrode which includes indium tin oxide (ITO), an ohmic characteristic between a second semiconductor layer and the second electrode is improved and a driving voltage is also improved. An embodiment relates to a light emitting device comprise a capping layer that can overlap the second semiconductor layer with the second electrode interposed therebetween and include a material of which a difference in thermal expansion coefficient with the second semiconductor layer is 3 or less. Therefore, since the capping layer is electrically connected to the second electrode, delamination and lifting of an interface between the second electrode and the second semiconductor layer is prevented, and reliability of the light emitting device is improved.

A light emitting diode (LED) is one of light emitting devices which emit light when a current is applied thereto. The LED has a high energy reduction effect because of emitting high efficiency light at low voltage. Recently, since a brightness of the LED is significantly improved, the LED is applied to various devices such as a backlight unit of a liquid crystal display device, an electric signboard, an indicator, and a home appliance.
An LED includes a light emitting structure having a first semiconductor layer, an active layer, and a second semiconductor layer, and a first electrode and a second electrode which are respectively in contact with the first semiconductor layer and the second semiconductor layer of the light emitting structure. Particularly, in a vertical light emitting device, a first semiconductor layer, an active layer, and a second semiconductor layer are selectively etched to form a groove through which a first electrode may be electrically connected to a first semiconductor layer.
Here, in the light emitting device, indium tin oxide (ITO) may be directly formed on the second semiconductor layer to improve an ohmic characteristic between the second electrode and the second semiconductor layer and a driving voltage. In addition, in the light emitting device, after a capping layer is formed on the ITO, an insulating layer, which covers the capping layer and exposes the first electrode, may be formed.
Here, since an interface between the ITO and the second semiconductor layer is a junction between a metal and a semiconductor, there is a problem in that the metal and the semiconductor are easily separated. In addition, the insulating layer formed under the capping layer is lifted, and thus contact failures may occur at electrodes which will be formed later, a substrate, and the like.


A semiconductor device includes a chip body having an uneven surface including at least two regions at different levels from one another, a through electrode penetrating the chip body and having an end which is exposed by the uneven surface of the chip body, a passivation layer disposed on the uneven surface of the chip body, and a bump disposed on the passivation layer and the exposed end of the through electrode and overlapping with the uneven surface of the chip body.

1. Technical Field
Embodiments of the present disclosure relate to semiconductor devices having through electrodes, methods of fabricating the same, electronic systems including the same, and memory cards including the same.
2. Related Art
Semiconductor devices employed in electronic systems may include various electronic circuit elements, and the electronic circuit elements may be integrated with a semiconductor substrate to constitute the semiconductor device, which may be referred to as a semiconductor chip or a semiconductor die. Before semiconductor devices including memory semiconductor chips are employed in electronic systems, the semiconductor devices may be encapsulated to have package forms. These semiconductor packages may be employed in the electronic systems such as computers, mobile systems or data storage media.
As mobile systems such as smart phones become lighter and smaller, the semiconductor packages employed in the mobile systems have been continuously scaled down. In addition, large capacitive semiconductor packages are increasingly in demand with the development of multi-functional mobile systems. To support scaling, efforts to put a plurality of semiconductor devices in a single package have been attempted to provide large capacitive semiconductor packages such as stack packages. Further, through silicon via (TSV) electrodes penetrating the semiconductor chip have been proposed to realize interconnection paths that electrically connect the semiconductor chips in a single stack package to each other.

Semiconductor devices having through electrodes, methods of fabricating the same, electronic systems including the same, and memory cards including same


The present invention relates to the field of image processing and methodologies to construct a descriptor from binary silhouette images. The method comprises the steps of; receiving a parametric equation of a closed planar curve, choosing nodes on the closed planar curve with equal intervals, generating a continuous scale space of the nodes on the curve by successively convolving the planar curve with a Gaussian filter and down-sampling it after each octave, calculating orientation vectors and orientation angle values for each sampled point at each interval of each octave, creating a orientation scale space (OSS) which is a matrix obtained from stacking each orientation angle value on top of each other, representing the outline with a descriptor including all the orientation vectors and their respective parameters position and scale.

It is known that there are methods and models to identify an object (or equivalently a "target") on a still image or a video frame. Such methods are used for example in infrared search and track (IRST) systems in which there is a sensor acquiring an infrared image of the scene under consideration and generally these images are converted into a greyscale format. This image consists of a two dimensional array of pixels which represent the infrared intensity at various locations. Currently there are systems and methods to extract and match features of the outlines of the input objects. These systems are used for example to determine a target of a known type and it will then be possible to interpret it accordingly. In such a method, it is desirable to represent different outlines efficiently to be able to store them in less space and speed the searching process up.
One such known method uses a curvature scale space (CSS) wherein the outline of the object which is a closed curve is used to generate the CSS. For this purpose, another initial calculation to fit a curve on the contour of the object is generally applied on a binary silhouette image of the object under consideration. In this known method, circle of curvature values are calculated over the closed curve and object descriptors are derived from a scale space representation of the outline. These are represented by graphs and peak values on this graph are used as feature parameters. Using such a representation, various shapes on images can be identified, matched or aligned. One of the main problems with the CSS method is that, it relies on the starting point of calculations on the silhouette curve. Since the silhouette is a closed curve around the object on an image, it does not have a defined starting point and this constitutes a problem when it is required to match or recognize outlines. As a solution to this problem, the peak values are currently being used for matching shapes, which is sensitive to noise and incorrect segmentation of outlines. When the outline is extracted with slight errors, the results may vary significantly with such an approach.
Another currently used method implements an ordering among the peaks on the graph acquired by the CSS technique. For example, peak coordinates are ordered with respect to the peak heights in a current implementation. Yet another technique is using the maximum peak as the starting point and representing the outlines starting from that peak. Again, these methods are prone to noise and incorrect segmentation or incorrect curve fitting.
The well known scale invariant feature transform (SIFT) method on the other hand, uses a scale space representation of a two dimensional (2D) greyscale image and generally the representative features of objects on the pixel image are found by computing difference of Gaussian images forming the scale space. Using this two dimensional method, various objects on pixel images can be represented by a list of salient points, can be compared, identified or matched. Disadvantages of the CSS outline feature extraction methods and the inability of the SIFT methods to find feature points representing only the outline of an object necessitate a new method. In some applications such as infrared imaging systems, targets or objects on the image generally have its features on its outline. Furthermore some objects do not require a complete representation but can be identified by only its outline. Storing feature points only on the outline takes less space and searching and matching will be much faster.
The current methods are not offering a reliable and efficient way of extracting, representing and matching silhouette image contour features on their own and a new methodology is introduced in this document.
The British patent document GB2393012, an application in the state of the art, discloses a method for searching a two-dimensional outline and comprises inputting a query, deriving a descriptor of said outline from a curvature scale space representation of the outline of the object, wherein the peak co-ordinate values of the CSS representation are ordered on the basis of the peak height values.
The United States patent document U.S. Pat. No. 7,430,303, an application in the state of the art, discloses a method for extracting and matching gesture features of image wherein a closed curve formed by a binary contour image of the gesture image is used to form curvature scale space (CSS) image and feature parameters are determined by extracting first plural peaks.
The United States patent document U.S. Pat. No. 6,711,293, an application in the state of the art, discloses a method and apparatus for identifying scale invariant features in an image by producing a plurality of difference images, blurring an initial image to produce a blurred image and subtracting the blurred image from the initial image to produce the difference image.
The application titled "System and Method for Identifying Scale Invariant Features of Object Outlines on Images" and numbered PCT/IB2012/050883 mainly focuses on extracting scale invariant features from closed planar curves (silhouettes) and representing these features on "silhouette feature histograms". Three main steps in the system and method may be defined as: curve extraction, feature extraction and descriptor construction.
Curve extraction step includes fitting a continuous curve on the contours of the silhouette and arc-length sampling this continuous curve. The next step, feature extraction includes curvature scale space construction and feature selection in this scale-space. The final step, descriptor construction uses the extracted frames as pixels on a rectangular (or radial) image, in which location of each pixel designates feature positions (over the curve) and scales (in the curvature scale space) and colour of each pixel represents the orientation of each feature (on the curve plane). In this final step, these images are matched to each other with a rotation and starting invariant manner, so as to accomplish object recognition tasks.
The technique gives satisfactory results. However due to the nature of the technique, the obtained features are generally extracted from the high curvature regions over the planar curve. Thus, lesser number of features is extracted from relatively smoother silhouettes. In this occasion, the descriptor image becomes sparse (including mostly empty pixels) since number of extracted features is relatively low. Matching two descriptor images with relatively different feature densities, in other words matching two silhouettes, one of which is smoother and the other is much curly, may become inefficient.

This patent is subject to a terminal disclaimer.

System and method for describing image outlines

Aselsan Elektronik Sanayi ve Ticaret Anonim Sirketi


A MEMS structure including a latch, a first lever, and a second lever. The first lever is designed to move past the latch as a result of flexure in the event of a change in a parameter in a first direction, and to latch in place at the latch if a change in the parameter in a second direction different than the first direction subsequently takes place. The second lever is designed to move past the first lever as a result of flexure in the event of the change in the parameter in the second direction, and to latch in place at the first lever if a change in the parameter in the first direction takes place after the change in the parameter in the second direction.

It may often be desirable to detect specific events associated with a change in a physical or chemical parameter. By way of example MEMS temperature storage sensors are known, comprising a latching mechanism consisting of two overlapping levers produced using IC processing and silicon micromachining techniques. One lever consists of p+-type silicon, and the other consists of polysilicon. After production, the levers can be brought to a latched state at room temperature using a probe tip, the levers being latched in place relative to one another in said latched state. If the temperature is reduced below a specific threshold value, the levers are released from the latched state, such that the element no longer returns to the blocked state even if the temperature changes again to room temperature. The event that the temperature had fallen below the threshold value can thus be detected.

MEMS structure and method for detecting a change in a parameter


Within each harmonic spectrum of a sequence of spectra derived from analysis of a waveform representing human speech are identified two or more fundamental or harmonic components that have frequencies that are separated by integer multiples of a fundamental acoustic frequency. The highest harmonic frequency that is also greater than 410 Hz is a primary cap frequency, which is used to select a primary phonetic note that corresponds to a subset of phonetic chords from a set of phonetic chords for which acoustic spectral is available. The spectral data can also include frequencies for primary band, secondary band (or secondary note), basal band, or reduced basal band acoustic components, which can be used to select a phonetic chord from the subset of phonetic chords corresponding to the selected primary note.

Some examples of speech processing or synthesizing apparatus or methods are disclosed in:    U.S. Pat. No. 5,406,635 entitled "Noise attenuation system" issued Apr. 11, 1995 to Jarvinen;    U. S. Pub. 2004/0181411 entitled "Voicing index controls for CELP speech encoding" published Sep. 16, 2004 in the name of Gao;    U.S. Pat. No. 6,925,435 entitled "Method and apparatus for improved noise reduction in a speech encoder" issued Aug. 2, 2005 to Gao;    U.S. Pat. No. 7,516,067 entitled "Method and apparatus using harmonic-model-based front end for robust speech recognition" issued Apr. 7, 2009 to Seltzer et al;    U.S. Pat. No. 7,634,401 entitled "Speech recognition method for determining missing speech" issued Dec. 15, 2009 to Fukuda;    U.S. Pat. No. 8,566,088 entitled "System and method for automatic speech to text conversion" issued Oct. 22, 2013 to Pinson et al;    U.S. Pat. No. 8,606,566 entitled "Speech enhancement through partial speech reconstruction" issued Dec. 10, 2013 to Li et al;    U.S. Pat. No. 8,812,312 entitled "System, method and program for speech processing" issued Aug. 19, 2014 to Fukuda et al;    U.S. Pat. No. 9,087,513 entitled "Noise reduction method, program product, and apparatus" issued Jul. 21, 2015 to Ichikawa et al;    U.S. Pat. No. 9,190,072 entitled "Local peak weighted-minimum mean square error (LPW-MMSE) estimation for robust speech" issued Nov. 17, 2015 to Ichikawa;    U.S. Pat. No. 9,570,072 entitled "System and method for noise reduction in processing speech signals by targeting speech and disregarding noise" issued Feb. 14, 2017 to Pinson;    Dieter Maurer, Acoustic of the Vowel: Preliminaries, Peter Lang A G, Bern 2016;    Bruno H. Repp, "Categorical Perception: Issues, Methods, Findings," SPEECH AND LANGUAGE: Advances in Basic Research and Practice, Vol. 10 p. 243 (Academic Press 1984), https://doi.org/10.1016/6978-0-12-608610-2.50012-1;    U.S. Pat. No. 9,147,393 entitled "Syllable based speech processing method" issued Sep. 29, 2015 to Fridman-Mintz (the inventor here);    U.S. Pat. No. 9,460,707 entitled "Method and apparatus for electronically recognizing a series of words based on syllable-defining beats" issued Oct. 4, 2016 to Fridman-Mintz (the inventor here); and    U.S. Pat. No. 9,747,892 entitled "Method and apparatus for electronically synthesizing acoustic waveforms representing a series of words based on syllable-defining beats" issued Aug. 29, 2017 to Fridman-Mintz (the inventor here).
Each of the last three patents listed above (each issued to Fridman-Mintz) is incorporated by reference as if set forth herein in its entirety.

Recognition or synthesis of human-uttered harmonic sounds


The present invention concerns a floating dock which is economical, durable and easy to install and maintain. The dock is comprised of uniform floating docking sections coupled together with rubber male-type anchors which fit into female-type receiving sockets on the docking sections. The two anchors of the couplers are secured together by a tie rod. The docking sections eliminate the need for boat bumpers, wood planking or other additional parts and expenses but allow for the attachment of desired accessories such as spud pipes, gang planks and tie-up cleats. The versatile docking sections can be arranged in an unlimited number of dock designs.

Floating docks are commonly used, particularly on lakes and bays, as a means of mooring boats and the like. Modular or sectional docks are frequently employed for constructing docks of various sizes and configurations. In the past, metal or styrofoam floatation cores encased in concrete shells have commonly been used as the basis for docking modules. The desired attachments are then connected to these structures to produce the dock. These modules, however, suffer from many disadvantages, such as deteriorating in certain environments, and are, therefore, limited in their applications.
The apparatus connecting modular docks together must be flexible enough to allow for the angular movement that will naturally occur from the action of wind and waves against the dock, yet be strong enough to keep the sections from breaking apart while under stress. Some prior art docks have attempted to solve these problems by securing the docking sections together with relatively long cables or springs. These devices, however, can leave large gaps between the individual docking sections resulting in an unsafe condition as users have to step over the gaps to travel along the dock. Additionally, such gaps allow more movement to occur between each docking section, thereby causing the overall dock configuration to lose its shape and the connecting apparatus to weaken. Thus, apparatus connecting the sections together, while being strong and flexible, should ideally also hold the sections closely together.
The docks should also be relatively easy to install as well as remove, if desired. As each boater's requirements will be unique, the docking sections should allow for a versatile array of dock arrangements to be constructed. Some of the prior art docks, however, can only be assembled in a limited number of configurations. Other systems require the owner to purchase extra parts, such as boat bumpers or wood planking, before the docks are complete and can be used.
Additionally, to achieve the required combination of strength and flexibility, many of the prior art docks contain complicated connecting apparatus that has a large number of parts and is difficult to assemble. Furthermore, these systems are more prone to wear and are much more likely to break down and require replacement. Yet these apparatus are also frequently difficult to access and repair, resulting in costly and laborious maintenance.
A need exists, therefore, for a modular floating dock that is simple to assemble and maintain, that is complete and ready to use after assembly and that is durable and flexible enough to be used in a variety of settings.


It has now been found that these and other objects of the invention may be attained in a vapor generation apparatus which includes a tube wall and an elongated first horizontal buckstay disposed at a first elevation. The apparatus also includes coupling means coupling the first horizontal buckstay to the tube wall, an elongated second horizontal buckstay disposed at an elevation that is higher than the first elevation. The apparatus also includes means for coupling the second horizontal buckstay to the tube wall. A first elongated vertical buckstay member has first and second ends and also includes for securing one end of the first elongated vertical buckstay members to one of the horizontal buckstay members. Second means for coupling the other end of the first elongated vertical buckstay member to the other horizontal buckstay, the means for coupling including a sleeve dimensioned and configured for receiving means extending from the other end of the first vertical buckstay member with sliding planar face to planar face engagement therebetween, the means for coupling allowing relative motion between the first vertical buckstay member the other horizontal buckstay member.

The invention relates to boilers such as large utility boilers that are disposed in a frame that is provided to withstand the internal furnace gas pressure. As the furnace approaches operating temperature, the furnace walls expand vertically and horizontally. Additionally, the pressure excursions within the furnace, either an increase or a decrease in pressure within the furnace, cause a resultant additional flexing of the tube walls either inwardly or outwardly in a horizontal direction.
It has become customary and necessary to provide an arrangement of flanged girder beams, typically referred to as buckstays, that extend around the furnace to provide additional support to the furnace wall and prevent the dishing of the furnace walls in a horizontal direction because of pressure variations. More particularly, the arrangement typically uses both vertical and horizontal structural members that are respectively known as vertical and horizontal buckstays.
Typically, the horizontal buckstays are disposed in bands around the perimeter of the furnace tube walls at vertically spaced intervals (often between 15 and 40 feet) throughout the height of the furnace wall. Horizontally, the buckstays on opposite walls of the furnace are interconnected through buckstay ties so that the reaction of one buckstay is resisted by the reactions of the buckstay on the opposing wall so it can counteract the pressure forces acting on the furnace walls. It has been customary to provide vertical support members to interconnect adjacent buckstays with a connection that permits a sliding action that permits relative movement between the furnace tube wall with which a buckstay cooperates and the buckstays themselves. As the furnace expands in a vertical direction the effect on the various levels of buckstays will be different. This will be apparent because the elongation of the furnace tube walls will be different at different points in the furnace. This relative vertical expansion between the furnace tube wall structure and the buckstays will produce a very high localized bending moment on the buckstays. It has been customary to relieve bending moments with these vertical support members which extend between neighboring buckstays. Arrangements for relieving or preventing the bending movement of this type are disclosed in U.S. Pat. Nos. 3,461,847 and 3,861,360.
The invention also relates to an attachment to such buckstays that will cause the vertical buckstay to also act as a leveler. A leveler is a device that will provide lateral stability for the horizontal buckstay as well as maintaining its level position.
In such buckstay arrangements utilizing vertically extending support members for linking the vertically adjacent buckstays and absorbing the bending moment, the structural system is necessarily massive and also somewhat rigid. Therefore, the structural support system has a certain amount of inertia which must be overcome before the structural system can flex properly in response to pressure changes within the furnace and thereby absorb the pressure forces acting on the furnace walls. In the event there is a sudden change in furnace pressure, and explosive or implosive load may be exerted on the furnace tube walls over a very short period of time. In such a system as described above wherein the band of buckstays are interconnected in a vertical direction, it has been observed that the buckstay system may in some instance be incapable of responding to such a sudden change in furnace pressure without permanent damage to the buckstay system and/or the furnace wall.
The prior art apparatus that attaches the vertical buckstay to the horizontal buckstay is overly complicated. More particularly, one current design uses a pin in a slot of one of the in connections. Loading in a vertical buckstay that can be transmittal to the horizontal buckstay is small because of the line contact between the pin and the slot.

Vertical buckstay/leveler attachment to a horizontal buckstay


A power supply for generation of a mainly sinusoidal output voltage, the magnitude and frequency of which are adapted for driving of main power-operated apparatuses. The power supply includes means (10) for generating a DC voltage, a DC/AC converter (18) including controlled semiconductor switches (19,20,21,22) and an electric control device (30) for emitting to the semiconductor switches suitable commutating signals according to a predetermined program to keep the switches closed and open, respectively, such that the desired waveform for the output voltage is achieved. Sensing of a parameter associated with the load current of the power supply is associated with the load current of the power supply is provided and cooperates with the control device (30) such that upon the load current exceeding a predetermined value the commutating signals are cancelled. The commutating signals are thereafter reconnected after a period of time which is considerably less than half the period of the output voltage. The control device (30) emits commutating signals continuously with breaks determined by the load current exceeding the predetermined value.

The present invention refers to a power supply and, more specifically, a power supply which generates a mainly sinusoidal voltage to be used in supplying apparatuses that are normally operated from the main power.
In caravans and motor caravans electric apparatuses and other equipment are found which are operated by low voltage DC current from, for example, a car battery or the like. In addition, there is often other equipment which is operated from the main power and which can be used only when the caravan is connected to the main power, for example at a caravan site.
Now, it is desired to provide a power supply by which it will be possible to use main power operated equipment even when the caravan is not situated at a caravan site, or the like, and, accordingly, cannot be connected to the main power. Such a power supply could be comprised by a unit generating a DC voltage and being associated with a DC/AC converter which, by means of switching technique known in the art, converts the DC voltage to a mainly sinusoidal AC voltage of the desired magnitude, for example 110 volts or 220 volts. Suitably, the DC voltage generating unit could be a three-phase AC generator of the kind to be found in cars for their electric supply. A generator of the kind referred to comprises a rectifying device providing a DC voltage output from the generator. Such a generator together with a DC/AC converter constructed by known techniques can be provided in the engine compartment of a car or motor caravan and be terminated with an AC outlet. Then, by a suitable line, the passenger compartment of the motor caravan or a caravan connected to the car can be supplied.
A power supply of the kind referred to has to be protected against excess current and to this end protecting arrangements are provided which disconnect the power supply when the load current exceeds a predetermined value. The art offers a solution in case of a disconnection reconnection is allowed after the lapse a time period corresponding to one or two periods of the AC voltage. If inductive loads, such as an induction motor of a refrigerator or an air conditioner, are to be supplied, the delayed reconnection is a disadvantage as sufficient energy will not be supplied to the motor to have it rotate before disconnection takes place due to overcurrent. Hence, under certain conditions it may happen that the compressor motor in the refrigerator or in the air conditioner, respectively, cannot be started.

DC/AC converter with overcurrent protection by temporary shutdown