81 results about "Shift factor" patented technology

The present invention is intended to provide an ethylene copolymer having excellent mechanical properties and moldability, a process for preparing the copolymer, a resin composition containing the copolymer and uses thereof. The ethylene copolymer has the following properties: the copolymer comprises 90 to 99% by mol of ethylene constituent units and 1 to 60% by mol of C3-20 alpha-olefin constituent units; the ratio (Mz / Mw) of a Z average molecular weight (Mz) to a weight-average molecular weight (Mw), each molecular weight being measured by GPC, is in the range of 10 to 30, and said ratio (Mz / Mw) and the ratio (Mw / Mn) of a weight-average molecular weight (Mw) to a number-average molecular weight (Mn), each molecular weight being measured by GPC, satisfy the relation (Mz / Mw)>(Mw / Mn); the intrinsic viscosity is in the range of 0.5 to 9 dl / g; the ratio (n*0.01 / n*8) of a melt viscosity (eta*0.01) at a shear rate of 0.01 rad / sec, as measured at 190° C., to a melt viscosity (eta*8) at a shear rate of 8 rad / sec, as measured at 190° C., and the intrinsic viscosity (eta) satisfy the relation (eta*0.01 / eta*8)>=0.893x(eta)+1.0; and the absolute value of an activation energy (Ea) of a shift factor of melt viscoelasticity is not more than 4x104 J / mol.K.

A date palm seed-based lost circulation material (LCM) is provided. A date palm seed LCM may be manufactured by drying date palm seeds and grinding the dried date palm seeds to create a plurality of particles. The particles may have sizes less than 4 mm, from 1 mm to 2 mm, or from 2 mm to 4 mm. The date palm seed LCM may have a volumetric swelling greater than an LCM formed from tree nuts and may have a volumetric swelling of at least 0.3 cubic centimeters per gram. The date palm seed LCM may have a D50 shift factor less than an LCM formed from calcium carbonate and may have a D50 shift factor of at least 0.38%. The date palm seed LCM may have a stability index of at least 0.95. Methods of lost circulation control and manufacture of a date palm seed LCM are also provided.

To provide a magnetic toner which has superior low-temperature fixing performance and pressure roller anti-staining properties even in various forms of use, has been kept from image defects such as image non-uniformity even during long-time image reproduction and can achieve high-level image quality. In a magnetic toner having toner particles containing at least a binder resin and a magnetic material, the activation energy Ea (kJ / mol) that is determined from a shift factor aT120 in a master curve of the toner, prepared when 120° C. is set as reference temperature, and the activation energy Eb (kJ / mol) that is determined from a shift factor aT150 in a master curve of the toner, prepared when 150° C. is set as reference temperature, satisfy Expression (1), and the Ea is 110 kJ / mol or less:1.00≦Ea / Eb<1.20  (1).

An audio signal decoder for providing a decoded audio signal representation on the basis of an encoded audio signal representation has a decoder preprocessing stage for obtaining a plurality of frequency band signals from the encoded audio signal representation, a clipping estimator, a level shifter, a frequency-to-time-domain converter, and a level shift compensator. The clipping estimator analyzes the encoded audio signal representation and / or side information relative to a gain of the frequency band signals in order to determine a current level shift factor. The level shifter shifts levels of the frequency band signals according to the level shift factor. The frequency-to-time-domain converter converts the level shifted frequency band signals into a time-domain representation. The level shift compensator acts on the time-domain representation for at least partly compensating a corresponding level shift and for obtaining a substantially compensated time-domain representation.

The invention relates to a method and device for constructing low-density parity check-code checking matrix. The constructing method is easy and flexible to implement, because the combination of semirandom constructing mode and structured constructing mode is adopted; besides, the arrays in the basis matrix are arranged in a special manner, the characteristics of irregular codes are achieved and the regularity is ensured. Therefore, the invention not only ensures excellent performance of low-density parity check-code, but also facilitates realization of coding hardware. In addition, short-loop is avoided in the basis matrix during the constructing process, and equal circular shift factors occur in the model matrix; thereby, the checking matrix has no short loop after expansion, and the decoding effect is improved. The invention also provides a group of selected model matrixes that can be expanded into multi-code length. The low-density parity check-code checking matrix with multi-code rate has an extensive application scope and excellent performance.

The invention belongs to the technical field of civil marine navigation, and relates to a marine navigation radar signal simulation method. A three-dimensional computer aided design (CAD) model of an offshore ship target is built by adopting computer aided design technology, predication is conducted to radar scattering sectional area of the target by high-frequency electromagnetic calculation software, the scattering area sectional area is processed so as to obtain a one-dimensional range image of the target, and convolution is conducted to radar transmitted wave form and the obtained one-dimensional range distance; Doppler frequency shift factors are introduced according to states of target motion; distance attenuation factors are introduced according to located position of the target; and low pass filtering is conducted so as to obtain marine navigation radar signal simulation echo through adding a sea clutter model. According to the marine navigation radar signal simulation method, a navigation radar ship target echo sample base which is high in similarity in various characteristic spaces with actual radar echo signals is provided, and radar echo signal sources are provided for teaching and training of navigation radars and seamen.

A date palm seed-based lost circulation material (LCM) is provided. A date palm seed LCM may be manufactured by drying date palm seeds and grinding the dried date palm seeds to create a plurality of particles. The particles may have sizes less than 4 mm, from 1 mm to 2 mm, or from 2 mm to 4 mm. The date palm seed LCM may have a volumetric swelling greater than an LCM formed from tree nuts and may have a volumetric swelling of at least 0.3 cubic centimeters per gram. The date palm seed LCM may have a D50 shift factor less than an LCM formed from calcium carbonate and may have a D50 shift factor of at least 0.38%. The date palm seed LCM may have a stability index of at least 0.95. Methods of lost circulation control and manufacture of a date palm seed LCM are also provided.

The invention discloses an underwater acoustic anti-Doppler multicarrier modulation and demodulation method based on linear frequency modulation. The method comprises the following steps: step one, transmitting terminal multicarrier modulation is performed; step two, Doppler frequency shift factor estimation is performed; and step three, receiving terminal demodulation is performed. The invention also discloses a modulation and demodulation device of the underwater acoustic anti-Doppler multicarrier modulation and demodulation method based on linear frequency modulation. The device comprises a transmitting device and a receiving device which are interconnected. The method has advantages of being high in anti-Doppler capability, wide in applicability, diverse in realization method, low in cost, easy to realize, high in efficiency, etc.

The invention relates to a traffic flow prediction method based on a quick learning neural network with double optimal learning rates. The method comprises the following steps of: normalizing m continuous traffic flow historical data which serve as the input of a prediction network; initializing weights and stretch and shift factors of a wavelet basis function by using a three-layer neural network, wherein the shift factors and transfer factors of the wavelet basis function employ a first learning rate, and network weights employ a second learning rate; providing a learning rate array, and performing network training of the double optimal learning rates; and outputting values of a current moment to first (m-1) periods, which serve as the input of a trained network, performing reverse normalization, and thus obtaining a prediction value of a traffic flow at a next moment of the current moment. The method has the advantages that the first learning rate and the second learning rate employ the optimal learning rates during network training at each time, quick network training can be realized, and high-accuracy prediction of the traffic flow is realized.

The invention relates to a clustering routing method for a mobile sensor network. For the application environment of the mobile wireless sensor network, the LEACH protocol in a traditional wireless sensor network is improved, and the shift factor and the energy factor are added so as to select a node with relatively low moving speed and high residual energy to form a cluster header node. At the data transmission stage, the dynamic time slot allocation method is adopted, and time slots which are free due to the fact that nodes leave a cluster structure are marked as free time slots and allocated to new member nodes. Thus, the problem that transmission time slots need to be re-divided continuously due to the fact that sensors move is effectively solved, network energy consumption is reduced, network time delay is shortened, and the network lifetime is prolonged.

The invention provides a toner which is excellent in its low-temperature fixing property and high-temperature offset resistance regardless of the types of paper, and constantly provides high-quality images regardless of environments and does not generate image defects even after prolonged use. In a master curve of the toner at a reference temperature of 150° C., a difference between a storage modulus at a frequency of 0.1 Hz and a storage modulus at a frequency of 1000 Hz is set in a rage from 0 to 2.5×105 Pa, where the activation energy determined from a shift factor is brought to a range from 50 to 130 kJ / mol.

An improved bit mapping method and apparatus for a communication system is provided. A bit mapping method of the present invention includes arranging coded bits in a codeword in an order of recovery capability; setting a shift region including a number of coded bits; rearranging the coded bits in the shift region by shifting the shift region by a number of bits equal to a number of bits that is indicated by a shift factor; and mapping the rearranged coded bits into a modulation symbol in an order of reliability from a lowest reliability bit position to a highest reliability bit position of the modulation symbol.

The invention discloses an image encoding method and an image encoding device. The method comprises the following steps: dividing domain blocks according to a value block scale range; performing isomorphic transformation on a matrix composed of 4 low frequency coefficients obtained by performing wavelet transformation on the domain blocks; performing recursive partitioning on value blocks until scale of the value blocks is less than the maximum scale; performing wavelet transformation on the value blocks to obtain 4 low frequency coefficients, calculating a value block direction K1 and a domain block direction K2, calculating a luminance factor and a shift factor and error thereof if the K1 is identical with the K2, and judging if the error is less than 5; if yes, writing position information of the value block and the domain blocks, transformation information and value block scale information into a code stream file, or performing quadtree partitioning on the value blocks; and writingending information into the code stream file when all the value blocks find corresponding domain blocks. The invention accelerates encoding speed and effectively improves compression ratio and decoded image quality, thus realizing effective image compression.

The invention relates to a method for generating a machine carried interference synthetic aperture radar (InSAR) original echo wave. The method comprises: step 1: implementing position method of Fourier transformation (FFT) on equivalent back scattering coefficientª†1ú¼2(xú¼ª†), and then multiplying a phase function with defocus item and reducing and enlarging factor P1ú¢exp{j(ªš2 / alphaª†0ú®ª†ú½j[ª©1,2(ªš) / 4B]ª†2}; stp2: implementing distance FFT on the result form step 1, then multiplying a phase function with reducing and enlarging factor P2ú¢exp{j(1-ª©1,2(ªš)) / ª©1,2(ªš)BªÃ}; step 3: implementing distance inverse FFT on the result from the step 2, then multiplying a phase function with reducing and enlarging factor P3ú¢exp{-Jú¿1 / 4Bú®ª†2}; step 4: implementing distance inverse FFT on the result from the step 3, then multiplying a phase function with space constant exciting response function, distance horizontal shift factor and the reducing and enlarging factor P4ú¢Gú¿ªšú¼ªÃú¼ª†0ú®exp{-jªÃª†s1,2ú½j[ª©1,2(ªš)-1]BªÃ2}; step 5: implementing two dimensional inverse FFT on the result from step 4 and getting the needed original echo wave data h1ú¼2(xíõú¼ríõ).

The invention discloses a feedback blind equalization method of a dynamic wavelet neural network based on fuzzy control, which comprises the following steps: a) passing a transmitted signal sequence x(n) through an unknown channel h(n), and then superimposing on a Gaussian white noise N(n) to obtain an observation sequence y(n); b) processing an error signal e(n) by a constant modular algorithm (CMA) to obtain a tap coefficient c(n) of a linear segment formed by transversal filters in a wavelet neural network; c) passing an input value deviation E(n) and a deviation change deltaE(n) of a fuzzy neural network controller through a fuzzy neural network controller to obtain an iteration step change value delta mu of an extension factor and a shift factor of a wavelet function in a nonlinear segment formed by wavelet neural networks in a dynamic wavelet neural network; and d) sequentially passing the observation sequence y(n) through the dynamic wavelet neural network and a judger to obtain an output signal. The method has faster convergence speed and smaller steady-state error, thereby being completely applicable to underwater acoustic channels.

The invention discloses a method for constructing a mechanical property main curve of a viscoelastic material, which comprises the following steps: 1) performing a mechanical property test on the viscoelastic material to obtain a series of test curves; 2) arranging according to ascending order or descending order of the test temperature and converting all the curve data to logarithm data; 3) calculating shift factors of adjacent curves, when the shift factor is calculated, an area of overlapping areas of two curves is considered, the area of the overlapping areas as zero is taken as a criteria to obtain the shift factor; 4) calculating the shift factor of each curve relative to the assignment reference curve, and shifting the relative curve to construct a main curve; and 5) if the test curve contains peak value curve, performing decomposition on peak value curve, calculating new shift factor, and correcting the constructed main curve. According to the invention, the shift factor can be directly calculated according to test data, and the calculating formula is very simple, the constructed main curve is unique and definite, and the subjective uncertainty of a hand-operated shift mode and necessary fitting or interpolation by a current automatic shift method can be avoided.

An embodiment of the invention discloses a data compression transmitting and decompression method and an apparatus, relates to the field of wireless communication, and is used for optimizing a data compression scheme. In the method, a transmitting terminal divides data to be transmitted into packets, and as for each packet: a shift factor is determined according to a highest order bit of sampling point data of the largest value after a sign bit is removed in the packet, and left shift is conducted respectively for data bits of the sampling point data in the packet according to the shift factor; quantization processing is carried out respectively for the sampling point data after the left shift, so that the number of bits of the sampling point data after the quantization processing is equal to the target number of bits of compression; and the shift factor and the sampling point data after the quantization processing are transmitted to the receiving terminal, the receiving terminal carries out de-quantization processing respectively for the sampling point data, right shift is conducted respectively for the data in the sampling point data after the de-quantization processing according to the shift factor, and decompressed sampling point data are obtained. According to the invention, the performance of the data compression is optimized.

The invention provides a toner which is excellent in its low-temperature fixing property and high-temperature offset resistance regardless of the types of paper, and constantly provides high-quality images regardless of environments and does not generate image defects even after prolonged use. In a master curve of the toner at a reference temperature of 150° C., a difference between a storage modulus at a frequency of 0.1 Hz and a storage modulus at a frequency of 1000 Hz is set in a rage from 0 to 2.5×105 Pa, where the activation energy determined from a shift factor is brought to a range from 50 to 130 kJ / mol.

The invention discloses a high speed image matching testing system that uses hardware accelerator to realize FFT and reverse FFT operation, uses embedded processor to operate and control. It discloses the method to use the system to realize high speed image matching testing. It adopts the arithmetic of detecting shift factor and detecting rotating factor in application to realize high speed image matching testing and high accuracy and high throughput process to make image matching detecting more efficient and costs lower.

The present invention relates to an apparatus, method for adjusting depth characteristics of a three-dimensional image for correcting for errors in perceived depth when scaling the three-dimensional image, the method comprising: receiving three-dimensional image information comprising a stereoscopic image including a first image and a second image, the stereoscopic image having depth characteristics associated with an offset of the first and second images; determining a scaling factor indicative of a scaling for converting the stereoscopic image from an original target size to a new size; determining at least one shifting factor for varying the depth characteristics, the at least one shifting factor indicative of a relative shift to be applied between the first and the second images, wherein the at least one shifting factor is determined in accordance with the scaling factor and at least one depth parameter derived from the depth characteristics; and performing the relative shift between the first and second images in accordance with the shifting factor for adjusting the offset of the first and second images.

The invention provides a method for performing data normalization processing by use of a DMA (direct memory access) controller. The method comprises an arithmetic operation processing step and a number move normalization processing step, wherein the number move normalization processing step comprises the following steps of: configuring the value of a normalization deflection bit register in the DMA controller according to a normalization shift factor output by the arithmetic operation processing, and configuring a DMA number move control register; reading the original bit width data from a data source memory by the DMA controller through reading control, and storing the original bit width data into a DMA internal cache register; performing data normalization processing according to the value of the normalization deflection bit register to obtain the deflected bit width data; sending the deflected bit width data to a destination address for storage; if the number move is finished, sending a DMA number move interrupt signal; otherwise, repeating the processes. With the adoption of the method, complete streamline operation can be realized in the whole arithmetic operation processing process, the time overhead is reduced, and the hardware operation processing efficiency can be improved without causing more additional overhead.

The invention provides an operation method for FFT. The method comprises the following steps: performing block floating point operation, moving data blocks leftwards or rightwards to regulate the signal power of FFT input during operation, performing data regulation according to an internal calculation result of each stage after the data operation of each stage by virtue of a special block floating point operation module, storing a set of data sharing a shift factor with an independent data field on hardware, and dividing result data by a preset gain to obtain correct data after operation, wherein the shift factors of the data blocks in block floating points are determined by maximum values of all the data in the whole data blocks. According to the floating point operation method, conflicts between a fixed-point algorithm and a floating point algorithm are solved, floating point operation efficiency is improved, and cost is lowered.

The invention provides an aging life evaluation method for a carbon-fiber composite core wire.The method comprises the following steps that 1, shift processing is conducted on creep test data of the composite core wire on the basis of a time-temperature equivalence principle, and a corresponding time-temperature shift factor is obtained; 2, shift processing is conducted on a test result obtained in the first step on the basis of a time-stress equivalence principle, and a corresponding time-stress shift factor is obtained; 3, the carbon-fiber composite core wire is evaluated by means of a time-temperature-stress equivalence principle; 4, fitting is conducted on an obtained creep strain master curve by means of an improved Findley model.According to the aging life evaluation method for the carbon-fiber composite core wire, influences of temperature and stress on wire creep behaviors in the practical use process of the novel carbon-fiber composite core wire are considered overall, and the aging life evaluation method can be well applied to service life prediction of the novel carbon-fiber composite core wire.

The invention relates to a method for measuring large linearity measuring range data fusion by means of compound color super resolution differential confocal measurement, belonging to the ultraprecise three-dimensional microstructure surface measuring field; firstly, formula 1 and formula 2 are utilized to respectively calculate output information of a first and a second super resolution differential confocal measuring branches, wherein, formula 3 is the actual output light intensity information of a first and a second measuring branches which are respectively obtained by adopting a compound colour super resolution differential confocal measuring device, (the formula 1, the formula 2 and the formula 3 are shown at the upper right side); Gamma1 and Gamma2 are intercepted to obtain effective output Gamma1 and Gamma2, and finally a systemic linear output fusion function (see the formula 4) is constructed and is output as the systemic final displacement response, wherein, GammaB' is a shift factor, lambda1and lambda2 are the wavelength of the first and the second measuring branches. The method remains the advantages of high space resolution and inhibiting common mode additive noise and linear range extension of the compound colour super resolution differential confocal measuring, can inhibit interference of multiplicative noise, and can obtain output characteristic curve with better linearity and larger linear measurement range.

The invention discloses an SLM method for lowering the peak-to-average power ratio of an SFBC MIMO-OFDM system. Information source bits of each antenna pass through a baseband modulation unit and a series-parallel-connection conversion unit, are subjected to different phase rotation, and then are subjected to IFFT modulation to obtain time domain signals, time domain odd-even signals are obtained through the circulation shift property of time domain signals of an FFT, and the time domain odd-even signals are subjected to different lengths of time domain circulation shifts and then subjected to time domain equivalent SFBC encoding to obtain alternative sequence pairs with different PAPRs. On the basis of a traditional SLM algorithm, more alternative sequence sets with different PAPRs can be obtained only through circulation shift and phase rotation of the time domain signals, and the PAPR inhibition performance is improved. Meanwhile, a receiving end recovers the odd-even signals, circulation shift factors and phase rotation factors by comparing the distance between a reverse rotation sequence and a nearest signal constellation point, and sideband secondary information does not need to be transmitted.

The present invention discloses a block-interleaved frequency division multiple access-based passive optical network transmission method. The method includes the following steps that: channel response is measured through a DSP (digital signal processing) method; at a transmitting end, user information is modulated, pre-channel compensation is performed on a downlink at the symbol blocks of an OLT (optical line terminal), in an uplink, rear channel compensation is performed on the OLT by inserting a training sequence, a modulated symbol block of which the length is P is repeated by K times, a symbol block of which the length is P*K is subjected to the effects of M paths of different shift factors, so that M paths of signals are generated and are multiplied by corresponding phase shift factors, and phase shift output is added, so that a B-IFDM (block interleaved frequency division multiple access) symbol block can be obtained, a cyclic prefix is added, shaping and filtering are carried out, and obtained signals are transmitted; and at a receiving end, after operation such as filtering, down conversion, de-mapping and decoding is performed, transmitted original bit information is restored. With the method of the invention adopted, requirements of the transmitter of an ONU end (optical network unit), for modulators and amplifiers, are lowered, the cost of a user side can be saved, the implementation of B-IFDMA is simple, and the complexity of the algorithms and devices of the transmitting end is decreased.

A controller is applied to a vehicle including an engine (11) and a motor generator (12 and 13) as power sources of the vehicle and a battery (20) that transfers power with the motor generator. The controller charges the battery with a regeneration power that is a power regenerated by the motor generator when the vehicle is decelerated. The controller includes a SOC prediction unit (39, 50 and 205) to predict a SOC indicating a remaining capacity of the battery in a scheduled travel route of the vehicle, based on a predicted result of a road grade and a vehicle speed in the scheduled travel route, a discharge control unit (39, 52, 206, 208 and 301 to 303) to execute a discharge increasing control to previously increase a discharge quantity of the battery to prevent the battery from becoming in a saturation state based on a predicted SOC that is the SOC predicted by the SOC prediction unit, when the discharge control unit determines that the battery becomes in the saturation state where the battery cannot be charged with the regeneration power based on the predicted SOC, a determination unit (39 and 105 to 109) to determine whether a behavior of the predicted SOC shifts from a behavior of an actual SOC or determine whether a SOC shift factor occurs, after a start of the discharge increasing control, where the SOC shift factor is a vehicle control or an environment change that predicts the behavior of the predicted SOC shifts from the behavior of the actual SOC, and a correction unit (39, 110, 201 to 209 and 301 to 303) to correct the discharge increasing control by executing a prediction of the SOC in the scheduled travel route again, when the determination unit determines that the behavior of the predicted SOC shifts from the behavior of the actual SOC or determines that the SOC shift factor occurs.

An embodiment of the invention provides a pilot frequency sequence distribution method and a pilot frequency sequence distribution device based on a massive multiple-input multiple-output system. The method specifically includes: within a set time interval, aiming at every terminal user, judging whether the terminal user belongs to an edge user or not according to an acquired large-scale fading factor value of every terminal user; if yes, selecting a pilot frequency sequence from a first set and distributing the selected pilot frequency sequence to every terminal user; otherwise, selecting a pilot frequency sequence from a second set to serve as an initial pilot frequency sequence, obtaining a target pilot frequency sequence according to the initial pilot frequency sequence and a stored linear phase shift factor, and distributing the target pilot frequency sequence to the terminal user, wherein pilot frequency sequences in the first set are different from pilot frequency sequences in the second set, the pilot frequency sequences, stored in first cells, in the first set are different, and linear phase shift factors stored in the first cells are different. By the pilot frequency sequence distribution method and the pilot frequency sequence distribution device based on the massive multiple-input multiple-output system, pilot frequency pollution among the cells can be reduced.

The invention discloses a novel instantaneous-current-direct-control-based pulse width modulation current tracking control method, which relates to the field of current tracking control methods for grid-connected inverter equipment in the field of power electronics. When output current regulation is performed in each cycle, an instantaneous voltage value of a direct current side and an instantaneous voltage value of a power grid are sampled, the action of effective instantaneous current vectors of an inverter in different on / off states is analyzed to obtain a control formula for instantaneous current shift factors, the action time of each effective instantaneous current shift factor at a corresponding moment is calculated, and control over the action time of different instantaneous current shift factors is realized in the next regulation cycle in a pulse width modulation way by utilizing functions of a pulse width modulation (PWM) peripheral of a digital signal processor (DSP) chip to finish the shift of a current instantaneous current vector to an instantaneous reference current vector of the next moment, thereby fulfilling the aim of controlling the reference current tracking of output current. The method is convenient to use, simple in operation, quick in current tracking response and low in deviation, and compared with the conventional methods, is highly advanced.

The invention discloses an asphalt aging performance prediction method based on isothermal thermal analysis kinetics, belongs to the technical field of road asphalt pavement durability, and solves problems that an asphalt aging process cannot be predicted accurately and more practical asphalt aging performance prediction cannot be provided for pavement management and maintenance work when attenuation of a macroscopic performance index of the asphalt is adopted to speculate a pavement performance degradation degree at present. The asphalt aging performance prediction method provided by the invention comprises the following steps: firstly, selecting an asphalt sample, testing with a thermal analyzer, simulating thermal-oxidative aging of the asphalt to obtain TG and DTG data and a char yieldof the asphalt; secondly, selecting a reaction mechanism function corresponding to the asphalt aging process according to a chemical structure, a functional group and thermal stability change of theasphalt aging process to establish an isothermal thermal analysis kinetics model of the asphalt; finally, using an aging-time equivalence principle to analyze equivalence of the asphalt aging processand time, calculating an isothermal aging shift factor by an Arrhenius equation to predict the asphalt aging performance, thereby providing a basis for decision-making of an asphalt pavement maintenance scheme.