摘要:
Circuits perform row-by-row matrix generation for encoding and decoding of data blocks. They perform fast algebraic generation of high performance low density parity check (LDPC) matrices suitable for use in a wide range of error correction coding and decoding (ECC) applications. Circuit operation is based on a mathematical Cyclic Ring method that enables matrices of any size to be generated from a simple set of initial parameters, based on user-defined performance requirements. The main steps for generating a parity check matrix (H) are selection of an RG matrix structure, selection of Group Ring elements, generating the sub matrices for the RG matrix by a row filling scheme, generating the RG matrix by a cyclic arrangement of the sub matrices, and generating the parity-check matrix by deleting suitably chosen columns from the RG matrix to achieve the desired performance and then transposing the matrix. A circuit performs data encoding or decoding by receiving initial vectors calculated from row vectors of a previously-generated parity check matrix H, cyclic shifting the vectors to generate a desired output row of the parity check matrix H, re-arranging the operation order of the vectors depending on the RG matrix structure and the chosen row, operating on the vectors on information to be encoded.
摘要:
The present invention relates to a damper for damping the reactionary motion of a wave energy conversion device to wave motion, comprising a damping energy absorber (7) having a reversible non-linear stress-strain response, arranged to damp the reactionary motion of the WEC. According to a first aspect, there is provided a damping structure (2) for a wave energy conversion device (1). The structure comprises a fixed member (6), and a damping member (7) having a reversible non-linear stress-strain response. The present invention also relates to a mooring component (2) for a mooring system (1) and to a method for manufacturing a mooring component (2). The component comprises a deformable element (6) having a reversible non-linear stress-strain response, wherein the response is a composite reversible non-linear stress-strain response.
摘要:
A mooring component for use in mooring system comprises a plurality of deformable elements having a reversible non-linear stress-strain response. The deformable elements are formed from elastomeric materials and have different lengths and/or cross-sectional areas and/or are formed from different materials. The overall response of the component is a composite reversible non-linear stress-strain response that is a combination of the responses of each of the plurality of elements. The stress-strain response of the component may be tailored to the expected environmental loading for the location at which the mooring system is to be used.
摘要:
A mooring component comprises a plurality of different deformable elements formed of an elastomeric material. The component has a tensile length L and at least one of the elements has a length L′
摘要:
A mooring component comprises a plurality of different deformable elements formed of an elastomeric material. The component has a tensile length L and at least one of the elements has a length L′
摘要:
The invention provides a drop-on-demand printer having a row of ink ejection locations for ejecting plural ink droplets, each ejection location having an associated ejection electrode for causing electrostatic ejection of the droplets from the respective ejection location. An intermediate electrode system has one or more rows of intermediate electrodes 3 spaced from the ejection locations between the ejection locations and a substrate on to which the droplets are printed during use. Plural conductive tracks 5 are provided, each corresponding to a respective intermediate or ejection electrode 3 and supplying a voltage to an electrode in use. Tracks 5 have a resistive element 14 either disposed immediately adjacent the corresponding electrode or actually forming the electrode 3.
摘要:
A semiconductor self-pulsating laser diode (1) comprises a wave guiding layer (2) sandwiched between lower and upper cladding layers (4, 5). A current blocking layer (8) defining a slot (10) through which pumping current is directed through the laser diode between upper and lower contact plates (5, 6) defines an active wave guiding region (15). The current blocking layer (8) is shaped by the formation of longitudinally extending recesses (12) for defining the active wave guiding region (15) such that a central pulse light generating region (17) is formed surrounded by an outer light propagating region (18). As the laser diode is continuously pumped, an effective step change in refractive index between the wave guiding layer (2) and the outer light propagating region (18) is formed, and the carrier density and refractive index profiles across the active wave guiding region (15) vary as each light pulse cycle progresses. Initially, the carrier density in the central pulse light generating region 17 rises relative to the carrier density in the light propagating region 18 until the difference between the refractive index of the pulse light generating region 17 and the refractive index of the light propagating region 18 is at its greatest, and the carrier density of the pulse light generating region 17 reaches its lasing threshold value. At this stage lasing commences in the active wave guiding region 15. Lasing in the pulse light generating region 17 progressively reduces the carrier density therein, which in turn progressively reduces the relative difference between the refractive index of the pulse light generating region 17 and the light propagating region 18 until the refractive index of the pulse light generating region 17 approaches the refractive index of the light propagating region 18, thereby increasing guiding of lasing light into the pulse light generating region 17 for emission of the light pulse therefrom. At that stage the carrier density of the active wave guiding region 15 falls below its lasing threshold value, thus extinguishing the lasing light, and the next light pulse cycle commences.
摘要:
The present invention relates to a damper for damping the reactionary motion of a wave energy conversion device to wave motion, comprising a damping energy absorber (7) having a reversible non-linear stress-strain response, arranged to damp the reactionary motion of the WEC. According to a first aspect, there is provided a damping structure (2) for a wave energy conversion device (1). The structure comprises a fixed member (6), and a damping member (7) having a reversible non-linear stress-strain response. The present invention also relates to a mooring component (2) for a mooring system (1) and to a method for manufacturing a mooring component (2). The component comprises a deformable element (6) having a reversible non-linear stress-strain response, wherein the response is a composite reversible non-linear stress-strain response.
摘要:
A laser diode (1) having an optical path (15) defined in an active layer (2) which is sandwiched between a substrate layer (3) and a top layer (4) and defined by a ridge (14) formed in the top layer (4) outputs laser light of a single predetermined wavelength. Refractive index altering grooves (21) extending transversely in the top layer (4) are provided at spaced apart locations for altering the refractive index of the active layer (2) along the optical path at partial reflecting locations (20) for causing partial longitudinal reflections of the laser light generated in the optical path (15) so that standing waves or harmonics thereof of the single predetermined wavelength are set up between the respective partial reflecting locations (20) and a first mirror facet (8) in the optical path (15). In order that the standing waves set up between the partial reflecting locations (20) and the first mirror facet (8) are harmonics of the predetermined single wavelength, the refractive index altering grooves (21) are located along the ridge (14) for forming the reflecting locations (20) at distances from the first mirror facet (8) which correspond to the effective length of the optical path (15) resulting from the affect of the inclusion of the reflecting locations (20) rather than at locations corresponding to the actual length of the light path (15).
摘要:
A bicycle safety light is mounted on the spoke of a bicycle wheel for rotation with the wheel. The light includes a light transmitting, refractive housing with an internal light and light operating circuit. The light is driven by a flasher circuit to produce a flickering effect. The flasher circuit itself is initiated by a motion sensor that senses any motion of the bicycle wheel. A time delay sustains operation of the flickering light for a predetermined period between activations of the motion sensor.