最新刊期
卷 40 ， 期 1 ， 2008
- 摘要：Abstract:Based on numerical simulation, the effect of base aerator on the length of lateral cavity has been analyzed.The result indicates that the size of base aerator has obvious influence on the length of lateral cavity. The bigger the base aerator is, the longer the lateral cavity. It is mainly because that, the variety of base aerator will change the pressure distributions of jet flow, which nfluences the diffuse velocity in the lateral direction.
- 1881
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- 18
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发布时间：2023-11-28 - 摘要：Abstract:The principle of set pair analysis (SPA) was introduced, the importantance of the value of i in SPA was pointed out, and the drawbacks of general approaches to the value of i was explained. Based on statistical test, a new approach to determine the reasonable value of i was precented attempted combined related coefficient of the set pair with kind coefficient. The results showed that the value of i in SPA is related to pair analysis to related coefficient of the set pair, variation coefficient and kind coefficient. The results about SPA should be helpful to hydrology and water resources.The reasonable outcome may be helpful in the field of hydrology and water resources.关键词：set pair analysis;relational degree;the value of i;related coefficient
- 2024
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- 4
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发布时间：2023-11-28 - 摘要：Abstract:关键词：seepage flow;anisotropic;technique of rotational control volume;local coordinate
- 1756
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- 8
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发布时间：2023-11-28 - 摘要：Abstract:It is found that most of incipient velocity formulas’ incipient coefficient K is a variant by analyzing and comparing some existing incipient velocity formulas. This paper points out the reason why coefficient K is variable. Theoretical analysis indicates that the coefficient K should not be a constant even for uniform sediment, while K should vary with the change of incipient condition, which is why many kinds of incipient velocity formulas are not accurate enough. Flow depth, non uniformity, and shape of sediment, and the relativity between the size of sediment and flow depth are factors which influence incipient condition. A incipient velocity formula is put forward based on these factors, and agrees well with the field and experimental data. Through comparison,it is found that the formula is superior to Zhang Rui jin’s formula, Shamov’s formula and Zhang Qi wei’s formula.关键词：non uniform sediment;incipient velocity;incipient coefficient;incipient condition
- 1922
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- 8
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- 1
发布时间：2023-11-28 - 摘要：Abstract:In order to study regional flood risk, to develop hazard maps, alarm systems and emergency plans for flood controls, floods due to dam break have become an important issue of study because of their properties of highly un predictability and destructivity. A parameter model, a relatively simple and physically based model and an instantaneous dam break model are proposed in this paper for the study jointly. A case study was carried out in the Quan min reservoir located in Guang an municipal of Sichuan Province. Results indicate that the accuracy and the variation range of the predications can be made more accurate and certain by applying the three models together for the study of dam break floods. Therefore, an effective flood control measure can be developed based on the results of the study. In addition, whether an emergency plan should be started or not in real time operations can be made accordingly on the basis of the results predicated.关键词：flood due to dam break;prediction method;flood control
- 1925
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- 24
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- 4
发布时间：2023-11-28 -
Symmetry Bifurcation and Chaos of the Poincaré Map, in a Three degree-of-freedom Vibro impact System
摘要：Abstract:A three degree-of-freedom vibro impact system with symmetric constraining stops is considered. The Poincaré map of the system is established, and the symmetry of the Poincaré map is derived in detail. The theory of bifurcation of fixed points is applied to such model, and it is shown that the symmetry of the Poincaré map suppresses codimension 1 period doubling bifurcation, Hopf flip bifurcation and pitchfork flip bifurcation of symmetric period n-2 motions. It is also proved that both the two antisymmetric period n-2 motions have the same stability. By numerical simulations, pitchfork bifurcation, Hopf bifurcation and Hopf Hopf bifurcation of symmetric period n-2 motions are represented.Besides,the routes to chaos after pitchfork bifurcation are studied in the forms of the phase portrait in the projected Poincaré section.关键词：vibro-impact system;symmetric period n-2 motion;Poincaré map;bifurcation;chaos- 2566
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- 42
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发布时间：2023-11-28 - 摘要：Abstract:Based on the model test, this paper studied the wall pressure and the pulsation characteristic of flood discharge tunnel with horizontal swirling flow. Results indicated that,for various flow patterns,wall pressure increase with the H and h increases,and the longitudinal wall pressure decreases along the tunnel.In the scope of Z/D=0.5～4.5,the intensity of pressure changes sharply,the nature of transition section is extremely obvious,the rule is different when the fluid pattern is different.The basic frequency of pulsation pressure,which belongs to the low frequency scope，is in 0.03~1.6 Hz.The dominant frequency mainly concentrates in 0~20 Hz；The amplitude probability distribution of wall pulsation pressure is in the Gauss normal distribution;but in the head (Z/D=0~4.5) and tail (Z/D=29~horizontal section export) of the level section Cs,Ce are larger than the theoretical value slightly.关键词：horizontal swirling flow;flood discharge tunnel with inner energy;model test;pulsation pressure;time averaged pressure
- 1453
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- 8
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- 3
发布时间：2023-11-28 - 摘要：Abstract:Brazilian disc is popular sample used for the measurement of tensile properties of brittle materials like marble. In order to study the laws of the failure strains after temperature treatment under dynamic tension, the dynamic split tests of a series of Brazilian disc of marble were performed using split Hopkins pressure bar(SHPB) of 100 mm diameter. The failure strains of all types of samples in different strain rate were obtained with strain gauges stuck on the center of the sample and the test results indicated that the failure strains of all types of samples are increased with the increment of the strain rate, and the failure strains of marble without heat treatment (type A) and those with a constant temperature treatment at 50 ℃(type 50A) are increased slightly while those with a constant temperature treatment at 100 ℃(type 100A) are increased remarkably and the increment is bigger than that of type A and type 50A. The failure strains of the samples with a constant temperature treatment at 50 ℃ are similar with those without any heat treatment, and after the constant temperature treatment at 100 ℃ the failure strains are more than those of the others types. The failure strains and the strain rates are increased gradually with the increment of projectile speed, and when the speeds are in the same level, the failure strains and the strain rates of the samples with the constant temperature treatment at 100 ℃ are higher than those of the others, and the difference between them are increased gradually with the increment of the speed.关键词：marble;dynamic split tests;dynamic failure strain;Brazilian disc;stress wave
- 1453
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- 10
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发布时间：2023-11-28 - 摘要：Abstract:The fatigue life range for the suspenders of suspender supported arch bridges is from 3 to 16 years. So the suspernders will break and be repaired possibly many times during the whole service life of the bridge. The estimated fatigue life of the suspenders is not a definite value since the estimation is based on statistical analysis. That means that the moment when the suspender breaks can only be located in a range instead of an exact date. During the estimated possible fatigue life range, the suspenders and the bridge may break abruptly at any moment. That is to say, the bridge may be destroyed unexpectedly due to the undetermined fatigue failure of the suspenders.Based on the failure safety theory, the study on the failure safety suspender systems of the suspender supported arch bridges is carried out. This avoids the uncertainty of the statistical fatigue life estimation. The failure safety suspender systems make it possible that the bridge will not collapse abruptly and unexpectedly due to the failure of some suspenders of that bridge. And the repairment of the damaged or broken suspenders can be realized right after the suspender failure happens without the whole bridge being closed for traffic.
- 1602
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发布时间：2023-11-28 - 摘要：Abstract:Effect of setting structure joint for Xiaowan high arch dam is discussed considering thermal stress and water loads from construction period to operation period. A no thickness contact element is presented to simulate structure joint, uniaxial equivalent tensile softening model is adopted as constitutive model of dam concrete. FEM analysis is performed with the whole model and sub model in this paper. The computation results show that the tensile stress on dam heel is released. Setting structure joint on dam heel has little influence on the whole structure of dam. The results can offer theory references for design of Xiaowan High Arch Dam.关键词：Xiaowan High Arch Dam;structure jiont;FEM;sub model method
- 1613
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- 12
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发布时间：2023-11-28 - 摘要：Abstract:The stepped low pressurized water diversion system is a new type of gravity water supply system, which is simple in structure and water conservation weir is the pivotal structure. In this paper numerical models for unsteady flow result from inspection are established to simulate the overfall and well flow patterns respectively. The result of numerical simulation shows the surge chamber or open channel set between the bulkhead gate and downstream pipeline can alleviate hydraulic oscillation resulted from inspection. Then the alleviation effect is compared between the two alleviation sets.The research also find out that the improper area of alleviation set can enlarge hydraulic oscillation of the water level of downstream conservation weir well. At last,based on hydraulic control and analysis, the principle of optimization to water conservation weir well and alleviation sets is proposed. All the researches above can offer technical grounds for the design, meanwhile the optimization principle has broad application value.关键词：stepped low pressurized water diversion system;water conservation weir;water control;hydraulic resonance;hydraulic oscillation frequency
- 1444
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发布时间：2023-11-28 - 摘要：Abstract:In order to improve the efficiency of biological treatment of living sewage with rich nitrogen and phosphorus, and reduce the carbon source, the character of simultaneous nitrification and denitrification and biological phosphorus removal of Sequencing Batch Biofilm Reactor(SBBR) in treating living sewage under the condition of anaerobic /anoxic process was studied. An new Sequencing Batch Biofilm Reactor(SBBR) with soft carrer was used to treat real living sewage．Result showed that under the optimization situation of treating process, effluent TN removal rate was 80％，effluent TP removal rate was 84％. It demonstrated that it was possible to remove N and P simultaneous in SBBR. For the aim of obtaining efficient effect of both biological N and P removal, various influencing factors were studied. Among the influencing factors，DO and SRT were important to both N and P removal. DO was the key factor for the simultaneous nitrification and denitrification of SBBR. Reducing SRT was availability to removal phosphorus.关键词：Sequencing Batch Biofilm Reactor(SBBR);simultaneous nitrification and denitrification;biological phosphorus removal
- 2431
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发布时间：2023-11-28 - 摘要：Abstract:A set of device was designed for collecting tailpipe exhaust，by which all three states of exhaust were gathered directly from tailpipe. Particles were collected with particle sampler, gas phase with XAD 2 resin and poly urethane foam(PUF) in a U typed tube and liquor condensate with condensator. A representative sample of gasoline exhaust was getted. GC/MS was used to determine the component after samples were extracted by dichloromethane. The result showed that 90# gasoline exhaust contains 99 components. Monocylic aromatic hydrocarbons are the main component with 78.4%, aliphatic hydrocarbons are the second with 12.3%, polycyclic aromatic hydrocarbons are 0.4 %.In addition, a few of aldehyde and ester are found. Some preferential control contaminants were quantificationally analyzed.关键词：gasoline exhaust;sampling device;composition analysis;GC/MS
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发布时间：2023-11-28 - 摘要：Abstract:Loach protein was hydrolyzed by Alcalase 2.4 L,Protamex,Papain,PTN 6.0 S and Flavorzyme 500 MG to study the characteristics of different enzymes, as well as the nutritional compositions and scavenging activity on DPPH· of different protein hydrolysates. Results revealed that the protein utilization, the extraction rate of peptides, and the degree of hydrolysis of PTN 6.0 S and Papain hydrolysates were higher than those of others. All of the hydrolysates were rich in glutamic acid，tryptophan and aspartate. The amino acid compositions of hydrolysates were closer to the reference pattern of amino acids. The fractions with molecular weight more than 3000 Da could be hydrolyzed by all of the enzymes. The fractions with molecular weight less than 500 Da were in the main components. The hydrolysate using Alcalase 2.4 L had the strongest scavenging activity on DPPH·. Inferior to it were the hydrolysates of PTN 6.0 S and Protamex. The hydrolysate using Flavorzyme500 MG had the weakest scavenging activity on DPPH·.关键词：loach protein;hydrolysis;amino acid composition;distribution profile of peptide molecular weight;scavenging activity on DPPH
- 1763
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- 4
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发布时间：2023-11-28 - 摘要：Abstract:A photovoltaic material based on fluorene having dicyanomethylenefluorene unit in the main chain were synthesized,and characterized by FT IR and NMR. The polymer possess satisfactory thermal stability and machinability with thermal decomposition temperature (Td) of 448.1 ℃ and glass transition temperature (Tg ) of 146.6 ℃. The materials perform a good absorption around about 300~700 nm, covering a large part of the visible spectrum. Their effective reversibilities of redox were determined, and a correspondingly low bandgap of 1.86 eV was obtained. A photocurrent density of 0.079 mA/cm2, open circuit voltage of 0.75 V, fill factor of 0.249 and power conversion efficiency of 0.016% were achieved under illumination of AM 1.5 from a solar simulator.
- 1433
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发布时间：2023-11-28 - 摘要：Abstract:Differences of morphological structure and properties of common polyurethane (PU(a)) and thermo sensitive polyurethanes（TSPU(b)and TSPU(c)）were investigated. Differential Scanning Calorimetry (DSC), Positron Annihilation Lifetimes（PAL）and water vapor permeability (WVP) were employed to investigate the phase transitions of polyurethanes and evaluate the temperature influence on the free volumes (FV) and the WVPs of all PU membranes. TSPU(b) with a glass transition reversible phase and TSPU(c) with a crystalline transition reversible phase showed an obvious phase separated structure and a phase transition in designed temperature range(20~50 ℃). In addition, PAL study indicated that the radius of free volume holes(R) and the fractional free volume (fv) of TSPU are closely related to the phase transition temperature (defined as switch temperature, Ts), phase transition leads to dramatic changes in R and fv. When the temperature exceeds the Ts, the fv change from 1.6% to more than 9.0%, the average radius of free volume holes change from 0.23 nm to above 0.4 nm (Rb=0.418 nm, Rc=0.467 nm) and become larger than that of the water vapor (Rw=0.4 nm).Simultaneously, the WVPs of TSPU (b) and TSPU(c) membranes also showed a dramatic increase by 130%,160% respectively and thermo sensitive characteristics.关键词：thermo sensitive polyurethane;switch temperature;free volume holes size;water vapor permeability
- 1600
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- 8
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发布时间：2023-11-28 - 摘要：Abstract:By using UV adsorption spectrophotometer, micro electrophoresis potential analyzer, and X ray photo spectroscopy, the adsorption characteristics and surface electrochemical properties of polycarboxylate type superplasticizer（PCS）on gypsum surface and their subsequent effects on fluidity loss of fresh gypsum plaster with hydration time were studied. The results indicated that the adsorption behavior of PCS on gypsum particles follows a Langmuir isothermal adsorption model with an adsorption heat of 20.85 kJ/mol and an adsorption layer thickness of 7.5 nm. The 2p electron bonding energy of Ca element on gypsum surface takes place obvious chemical shift before and after the adsorption of PCS, which suggests that the adsorption of PCS belongs to chemical adsorption. The adsorption conformation of PCS superplasticizer is comb shaped, so it has a saturated low adsorption amount and a weak electrostatic repulsive effect, and its dispersion mainly comes from high steric hindrance effect generated by the adsorption layer. The steric hindrance is less affected by new hydration products, resulting in good dispersion stability.关键词：gypsum;superplasticizers;adsorption;ζ potential;steric hindrance;electrostatic repulsive force
- 1532
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- 40
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发布时间：2023-11-28 - 摘要：Abstract:Dental implants suffer a great variety of loading modes during normal chewing functions, which will initially cause fretting damages at the bone implant interface and might finally induce the failure of implant. Composite fretting tests of flat cortical bone specimens from fresh human mandible against pure titanium (TA2) ball was carried out on a test rig under laboratory controlled conditions. The imposed tiled angle was 45°, the vertical loads varied from Fmin (= 70 N) to Fmax (= 100 N and 200 N, respectively) at a constant loading speed of 12 mm/min, and the number of cycles varied from 1 to 5×104. Dynamic characteristics of composite fretting tests were recorded by the computer during the tests. After tests, morphologies and wear debris of fretting scars were observed by means of optical microscopy (OM), laser confocal scanning microscopy (LCSM) and scanning electron microscopy (SEM). The compositions of the mandibular cortical bone and wear debris were analyzed by energy dispersive X ray spectrum (EDX). There are only the trapezoid and elliptic mode F-D curves during the composite fretting tests of human mandible cortical bone. The friction energy dissipation varied drastically with the increase of the number of cycles under high load condition. The wear mechanisms of the composite fretting of mandible cortical bone were the combination of the adhesive wear, abrasive wear, cracking and lubrication of the human bone tissue debris.关键词：dual motion fretting;fretting wear;wear mechanism;human cortical bone of mandibular
- 2008
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- 8
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- 1
发布时间：2023-11-28 - 摘要：Abstract:In order to solve the issues existing in the electronic voting, such as voter privacy disclosure, registration center deceive voters and ballot forgery, etc. A new electronic voting scheme based on the principle of eletronic voting and the technology of ring signature was proposed. In this scheme, the serialized and blinded ballots were deliverd to legal voters,and a voter can select other eligible voter’s public key to make up a virtual voting group, sign the ballot using a ring signature algorithm, and accomplish the voting task.关键词：electronic voting;ring signature;RSA;blind signature
- 3035
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- 2
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发布时间：2023-11-28 - 摘要：Abstract:Aim at the problem of blind source separation of communication signals, a step size optimization equivariant adaptive source separation via independence (SO-EASI) algorithm was proposed based on the EASI algorithm. This algorithm adjusted the step size based on the steepest descent method and thereby greatly improved its convergence speed whether the step-size was initialized at a bigger or smaller positive number. Simulation results proved that SO EASI algorithm can effectively separate the communication signals blindly. Results showed that when the initial step size is equal to 0.02, the convergence speed of the SO-EAIS algorithm is 10 times that of fixed-step EASI algorithm and VS-EASI algorithm.关键词：blind source separation;communication signal processing;step-size optimization;convergence speed
- 2148
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- 2
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- 2
发布时间：2023-11-28 - 摘要：Abstract:In order to handle the uncertainties and complexities of multi-stage attack detection effectively, a novel detection model for multi-stage attacks based on Weighted Ordered Weighted Averaging (WOWA) and Fuzzy Cognitive Maps (FCM) was proposed. Based on Attack Intention Analysis, the WOWA-FCM detection model implemented the Cause Effect correlation of the primary intrusion alerts along with the vulnerability and configuration information of the target system utilizing Fuzzy Cognitive Maps, and implemented the effects fusion via WOWA aggregation operators. The WOWA-FCM approach was not only able to recognize the individual stages of a multi stage attack, construct the whole attack scenario, but also able to evaluate the global attack process and the security states of the target system dynamically. The WOWA-FCM model simplified the conventional multi-stage attack detection process, and provided with a better adaptability. The effectiveness of this approach was verified by the Mstream DDoS detection experimental results.关键词：multi-stage attack;Fuzzy Cognitive Maps(FCM);intrusion detection;Weighted Ordered Weighted Averaging operator(WOWA);alert correlation
- 1432
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- 30
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发布时间：2023-11-28 - 摘要：Abstract:In order to efficiently specify multi-enabling property which is an important character of concurrent systems using partial order logic, a new logic, flow event structure logic (FESL), was proposed. Flow event structures served as models for supporting the specification for casual properties between runs of concurrent systems, and two extra configuration qutifiers “A” and “E” which specifies the properties of configurations were introduced to establish the axiomation system for FESL. Completeness and soundness of axiomation system for FESL were proved. The proof showed the logic the power of specifying multi-enabling property.关键词：flow event structure;partial order temporal logic;configuration;axiom system
- 1914
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- 24
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发布时间：2023-11-28 - 摘要：Abstract:In order to solve the edge discontinuity produced by the edgeflow method used to detect the image edge, the edgeflow was made a variable into the level set equation and a multi-scale idea was also introduced into it. First, arough contour was found out by the way that the edgeflow vector, being acquired through the image with large scale, and it was put into the level set equation; Second, the rough contour was gradually optimized as an initial one in another level set equation of smaller scale when its edgeflow vector was calculated out and put into level equation to solve; Finally, the segmentation of image was carried out. The results showed that it eliminates the edge discontinuity and speeds up the curve evolution when applied to the segentation of conglomerate image.关键词：degeflow;multi-scale level set;image segmentation;conglomerate image
- 2013
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- 6
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- 2
发布时间：2023-11-28 - 摘要：Abstract:The quality of side information influences the overall Rate-Distortion (RD) performance of the Distributed Video Coding (DVC) codec. In order to optimize the RD performance of DVC by improving the quality of side information, based on the introduction of basic way to interpolation the side information, three different strategies was proposed to optimize the side information.Firstly,the initial motion vectors was obtained using traditional unidirectional motion estimation,then the Overlapped Symmetric Bi directional Motion Estimation and Adaptive Weighted Motion Field Filter were used to improve the motion field,and Weighted and Overlapped Motion Compensation was lastly used to reduce the block artifact. Experimental results showed that compared to other algorithms, the proposed strategies can significant improve the RD performance of the video coding system with out increase encoding complexity.关键词：Distributed Video Coding(DVC);Wyner-Ziv;motion compensated interpolation;side information
- 2274
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- 12
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发布时间：2023-11-28 - 摘要：Abstract:During the process of digitalizing the well logging graphs, in order to avoid the disturbance of automatic curve tracing caused by the coordinate grids, the coordinate grids should be deleted before tracing.To delete them effectively,a new method based on frequency domain filter was proposed, which is called as ‘+ shape and low pass filter’ method. First the ‘+ shape filter’ was used to get rid of the vertical and horizontal edges. Then the low pass filter was used to get rid of the rest of the grids, and a method was proposed to determine the filter radius automatically. The new method was proved to be effective to remove the even grids by the experiments,which provides a reference to research on deleting the grids in frequency domain.关键词：DFT;‘+ shape and low-pass filter’ method;coordinate grids deleting
- 2107
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- 6
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- 2
发布时间：2023-11-28 - 摘要：Abstract:The existing overlay multicast schemes have a common inherit performance limitation caused by transport layer singlehoming technologies. In order to improve the transfer performance of overlay multicast, a new network architecture of overlay multicast based on high fault tolerance and concurrent multipath transfer of transport layer multihoming was designed, which includes abstract service interface layer, transport service layer and overlay multicast layer. The QoS-satisfied multicast algorithm based on such overlay multicast architecture was presented, which established QoS-satisfied multicast tree and overlay traffic balance among the service brokers. The simulation showed that such new scheme eliminated the performance bottleneck such as QoS-satisfied ratio, multicast tree total cost, average link stress and average path length effectively.关键词：overlay multicast;transport layer multihoming;SCTP;QoS Satisfied Ratio
- 1614
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- 52
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- 0
发布时间：2023-11-28 - 摘要：Abstract:In order to improve signal noise ratio (SNR) of edge extraction, and to detect edge more effectively and exactly,according to fractional order differential difference function which was deduced from classical fractional differential G-L definition, an approximate fractional order differential Tiansi module was constructed. Experiments show that fractional differential operator can effectively extract edge information and has higher SNR than traditional operators.关键词：fractional differential;edge detection;differential order;cover module;peak signal noise ratio
- 2351
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- 22
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发布时间：2023-11-28 - 摘要：Abstract:In order to improve the accuracy of fractional order differentiator, a hybrid genetic algorithm was applied to design fractional order differentiator. The characters and design method of fractional order differentiator was analyzed, and through optimizing coefficients of corresponding IIR filter, the global optimum chromosome was obtained and high frequency deviation of fractional order differentiator designed by traditional methods was avoided. Simulation experiments demonstrated that the fractional order differentiator performance obtained in this paper outperforms to others and its magnitude response approaches to the ideal fractional order differentiator.关键词：fractional order differentiator;Genetic algorithm;fractional calculus;fractional control system;variation coefficient
- 1840
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- 32
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- 1
发布时间：2023-11-28 - 摘要：Abstract:Compensation for the geometric and thermal error is the most effective methods to improve the machining precision. These errors were classified and the normal modeling methods were given. A real-time error compensation controller was developed based on the CNC shift function of external coordinate system. The technology was implemented on CY-K360 CNC turning center and the position error of X axial and the Radial thermal error of the spindle were compensated.The result proved the new method's availability in accuracy improving.关键词：NC machine tool;error modeling;real time compensation;CNC controller
- 2002
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- 20
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- 7
发布时间：2023-11-28 - 摘要：Abstract:To resolve linear interpolation questions in three dimension,a new interpolation methods using bar elastic distortion theory was presented. According to the definition of interpolation,the equations of the bar elastic distortion can be used as a interpolation methods to make the flexibility and elastic coefficient have the means of mathematics and modify the qualifications.The interpolation equations can be fixed by the parameters g(gyi,gzi).This methods has specific means in physics and the arithmetic of it is simple.The curves produced by the methods have compact forms.It optimizes the B-spline methods and can be used in many fileds such as CAD and converse project.
- 1519
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- 2
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发布时间：2023-11-28 - 摘要：Abstract:In NC processing, only the straight line and circle arc can be processed directly , and the others must be fitted with them before processed. There are many methods of fitting curves with arc,but different shortage exists. An arc is built based on its length equal to the segment length of the curve approached ,the direction of the circinal center is judged according to the variety inclined of curve segment slope，so that convex curve is replaced with a convex arc.The overstep equation of triangle is simplified with expanding series to improve computing efficiency. The computation result shows the method is not only very simple to calculate,but also has high accuracy to approach the processed curve by an equal length arc.关键词：NC process;curve fitting;substitutive arc
- 1650
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发布时间：2023-11-28
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