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2008 Vol. 34, No. 11

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Environmental quality evaluation for submarine based on D-S theory
Pang Liping, Qu Hongquan
2008, 34(11): 1243-1246.
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The integrative environmental quality is very important to staff working in the submarine cabin. There are many factors affecting the integrated environmental quality in a submarine cabin, such as temperature, humidity, air trace contaminants, particle pollutants, microorganism and noise. To better evaluate thses factors contributing to the environmental quality, an integrated environmental quality evaluation was studied based on D-S(Dempster-Shafer) theory and analytic hierarchy process. Firstly, the specialists get the evaluation results with the AHP(analytic hierarchy process), but usually different specialists have different weight coefficients for the same environmental fact. Therefore, it is very difficult to deal with this issue. To solve the issue, the D-S was introduced to synthesize the different specialist results. The results could effectively fuse multi-specialists uncertainty evaluation results and improve its dependability.
Influence of constant pressure valve on boosting character of by-pass flow type ECHPS
Liu Yahui, Gao Feng, Ji Xuewu
2008, 34(11): 1247-1249.
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The actuator in by-pass flow type electronically controlled hydraulic power steering (ECHPS) was solenoid valve. Boosting characters of ECHPS whose solenoid valves with and without constant pressure valve were analyzed and measured. The results show solenoid valve with or without constant pressure valve in the ECHPS engenders different characters that all of the pressure in the character within the constant pressure valve would attain high value of the rated system pressure but would not without constant pressure valve. For the safety factors of driving and designing of system, the character with constant pressure valve in the solenoid valve is better than this without constant pressure valve.
Fuzzy control law design of hypersonic vehicle based on genetic algorithm
Li Huifeng, Wang Jian
2008, 34(11): 1250-1253.
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Considering the pitching channel of air breathing hypersonic vehicle X-43A as plant, flight control system was designed according to the 6 degree of freedom nonlinear model. The flight control system includes two loops, of which the structure is conventional mode. The guidance loop is a PD controller, while the control loop is composed of two fuzzy logic controllers. The guidance loop leads the vehicle to follow trajectory, when the control loop follows guidance command. Based on genetic algorithm, the optimization process of PD feedback parameters and fuzzy logic control rules was carried out automatically, which means expert knowledge and training data are not necessary in advance. This optimization process solved the problem of obtaining fuzzy logic control rules. Nonlinear dynamics, uncertainties and restrictions were contained in research on the control of trajectory, attitude and thrust. Simulations show that the method is able to satisfy both the robustness of flight control system and the convergence of optimization process on request.
LuGre-based compensation for friction in electro-hydraulic loading
Wang Xiaodong, Jiao Zongxia, Xie Shaochen
2008, 34(11): 1254-1257.
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In order to improve the control accuracy of electro-hydraulic loading system, the feed forward compensation method based on LuGre dynamic friction model was proposed to solve the friction problem. The mathematical model of electro-hydraulic loading system was built for friction simulation and compensator design purpose. The friction data acquired by experiments was analyzed,based on which the parameters of LuGre friction model were identified. The identified results, together with the LuGre model, were introduced into the mathematical model of electro-hydraulic loading system. The friction data in simulation result was compared with the actual one to verify the precision of LuGre friction model. The feed forward compensator was designed and the comparison experiments were performed. The experimental results show that this compensator can suppressed the control error caused by friction to as 30% as that without compensation.
Narrow-linewidth single-frequency single-polarization Er-doped fiber ring laser
Ou Pan, Jia Yudong, Zhang Chunxi, Wei Xingchun
2008, 34(11): 1258-1260.
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In order to acquire a stable narrow-linewidth single-frequency polarized Er-doped fiber laser, the ring fiber laser with a saturable absorber was studied. In the experiments, an un-pumped Er-doped fiber was used as saturable absorber to form an optical narrow-bandwidth filter, a fiber bragg grating with high reflectivity was adopted as coarse wavelength selective component, and a polarization-maintaining optical circulator with high extinction ratio was applied to acquire single polarization laser. The peak wavelength of the Er-doped ring fiber laser can be tuned from 1548nm to 1552nm by pulling the fiber bragg grating. The maximum output power was 55.4mW when the pump power arrived at 275mW. The 20dB linewidth of the Er-doped ring fiber laser was measured to be 3kHz with the fiber delayed heterodyne method. It was found that the polarization of the Er-doped ring fiber laser was very stable for a long term, and the degree of polarization was 99.9%. This narrow-linewidth single-frequency single-polarization Er-doped fiber laser can be used as stable signal source for coherent laser radar.
Framework for software reliability comprehensive evaluation based on grey system theory
Li Haifeng, Lu Minyan, Wang Zhixin, Li Zhen
2008, 34(11): 1261-1265.
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From the viewpoint of system engineering, a useful framework was explored for software reliability comprehensive evaluation based on grey system theory which has been acknowledged as a powerful technique for system comprehensive evaluation. According to the software quality model in ISO/IEC 9126, software reliability metrics were regarded as the evaluation index, and the grey relational degree between each metric and reliability was analyzed which can be used to identify the weights of metrics. Consequently the software reliability comprehensive evaluation method based on grey cluster theory was proposed. Finally, a primary experiment research was conducted to show that the framework for software reliability comprehensive evaluation based on grey system theory can reflect the level of reliability accurately with the values of these reliability metrics which can be collected easily in each development phase. Therefore the proposed framework is suitable for reliability engineering practice.
Resource conflict detection and management in implementation of multi-level and collaborative projects
Qiao Lihong, Wang Chao
2008, 34(11): 1266-1271.
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To solve the resource conflict problem in multi-level and collaborative engineering projects in aviation and aerospace industries, the detection of resource conflicts was studied using a temporal constraint network algorithm. In the algorithm, a task relationship model for temporal constraint networks was built. Based on the model, a linearization method was developed to deal with concurrent tasks, as well as an instantiation method to import temporal constraint data into the model. By implementing the procedures of the algorithm, the proposed conflict detection criterion can be applied to detect resource conflicts in engineering projects. To express and manage the detection results, an information model based on UML was established and multi-view approaches including Gantt chart, man-hour chart, and resource calendar view were used as standard expression mode. A project resource management prototype system was developed and examined with an example of aerospace engineering project to illustrate the effectiveness of the proposed approach to resource conflict detection and management.
Extended state observer-based fault detection and recovery for flywheels
Jin Lei, Xu Shijie
2008, 34(11): 1272-1275.
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Flywheels are main actuators of satellite attitude control systems, and fault detection and recovery of flywheels is significant on keeping the normal satellite attitude. A high fidelity open-loop system of flywheel was modeled and the second order nonlinear continuous extended state observer(ESO) was established via the nonlinear model. Under the assumption that the system external disturbances are minor and are neglected, fault in flywheel was regarded as the main system external disturbance. Therefore, by using ESO, not only the system state was obtained, but also the fault was estimated with exactness and swiftness. With the fault obtained, fault detection was accomplished without generating system residual, and fault recovery was also achieved by compensating the system input voltage, which ensures the normal flywheel speed and satellite attitude. The simulation results demonstrate the validity of this scheme.
Statistical language model adaptation based on N-gram distribution
Yin Jihao, Jiang Zhiguo, Fan Xiaozhong
2008, 34(11): 1276-1279.
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N-gram distribution can represent the characters of corpus correctly. So an approach was proposed for statistical language modeling adaptation, which is based on N-gram distribution. Given a large set of out-of-task training data, called training set, and a small set of task-special training data, called seed set, one statistical language modeling was adapted towards the special domain by adjusting the N-gram distribution in the training set to that in the seed set. The experiment results show prominent improvements over conventional methods. Compared with the simple interpolation method, the perplexity and word error rate decreases 11.1% and 6.9% respectively.
Design of coordinated control system for beam-carried cranes group based on RTK-GPS
Guo Zhongwei, Li Yunhua
2008, 34(11): 1280-1283.
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The coordinated control system for beam-carried cranes group used symmetrically laid two dual-frequency carrier phase real-time kinematic difference global position system(RTK-GPS) receivers to complete the large-scale beam-carrier-s position and direction measurement. Based on Kalman filter, the data fusion technology eliminated the volatility of the GPS data and improved the accuracy of location. The networked control system based on controller area network(CAN) bus combined the wireless network used for inter-crane communication to be as the foundation of the control system. Control strategy based on dual-closed-loop control achieved the synchronization of the beam-carried crane group. Practical application results show that the relative position deviation between the two cranes is not more than 0.1m, and relative heading angle deviation is not more than 0.1 degree.
Numerical simulation of heat transfer in rotating smooth square ducts using modified k-ω turbulence model
Tao Zhi, Xu Xueliang, Deng Hongwu, Zhu Jianqin
2008, 34(11): 1284-1287.
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A three-dimensional Navier-Stokes code with modified k-ε,k-ω(with new terms for Coriolis and rotational buoyancy) and standard k-ω turbulence models were used for prediction of flow and heat transfer characteristics for a rotating smooth square channel with radially outward flow. Comparisons between the calculation results of using different turbulence models were made with experimental data, test case is the rotation number(based on the inlet velocity and rotation speed) Ro =0.24; Reynolds number(based on the inlet velocity) Re =25000. The numerical results reveal that the heat transfer predictions have great discrepancy by using different turbulence models. For the present test case, the numerical results of using modified k-ω turbulence model give predictions that are in better agreement with the experimental data than using modified k-ε turbulence model and standard k-ω turbulence model.
Variable selection based on principal basis analysis
Wang Huiwen, Yi Bin, Ye Ming
2008, 34(11): 1288-1291.
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A principal basis analysis method based on Gram-Schmidt process was proposed.Information deleted by Gram-Schmidt process was explained and proved.Principal basis and introduced its construction method was defined.The concept of net information ratio was also put forward to measure the information retained in principal basis. This method selects information effectively from the large-scale variable set while excludes all the redundant variables and reduplicate information,on the promise that the loss of original information is minimized to obtain a mini-dimensional orthogonal basis. From different perspectives,the principal basis can not only retain original information to the utmost extent, but also ensure least similarity changes between elements. Case study was addressed to validate the rationality and effectiveness of this method.
Selective control mechanism for multi-datastream security in streaming media system
Xiao Chen, Ma Shilong, Lü Weifeng, Wang Lifeng
2008, 34(11): 1292-1297.
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Partial encryption and other media encryption schemes are effective approaches to encrypt the media data which are high volume and latency sensitive. However, use one media encryption scheme to protect all the media streams in a streaming media system will induce efficiency, scalability and security problems. To solve this problem, a security weightiness based dynamic optimal selective control mechanism for multi-datastream encryption was proposed. The idea of partial encryption was generalized from encrypting a subset of one stream to multi-streams. It can determine the optimum encryption algorithm with different security levels for each stream in the system, according to stream-s bandwidth, weightiness and other parameters. Since the simplified mathematical model is 0-1 knapsack problem which is NP-hard, a greedy heuristic incremental approximate algorithm was designed. Theoretical and experimental analyses show the approximate rate and speed of the algorithm are effective enough to support real-time applications. A prototype was implemented in an actual video conferencing system: Admire.
Quantitative evaluation of accelerated stress testing based on SSI
Li Xiaoyang, Jiang Tongmin
2008, 34(11): 1298-1302.
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In conducting accelerated stress testing (AST), to quantitatively evaluate reliability with respect to time by use of stress-strength interference (SSI) model, stochastic processes were introduced to describe stress and strength. Firstly,It was assumed that strength degradation and stress variation is drift and symmetric Brownian motion, respectively. Brownian motion SSI established by Basu involved reliability equals 1 when time equals zero. To overcome this problem, from engineering view, reliability of product was regarded as the result, which inherence reliability determined by design and manufacturing is in series with operation reliability decided by experiments and operation. Based on the traditional SSI and Basu-s model, time-dependent interference model of strength degradationⅠ (IMSDⅠ) was derived. With the combination of AST and accelerated degradation testing(ADT), data collection method in AST was improved. Finally, simulation example verified the correctness and applicability of the methodology proposed.
U-transformation finite element method in analysis of Reissner rectangular plates
Chen Fuli, Jiang Chiping
2008, 34(11): 1303-1306.
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The U-transformation method was applied to the Reissner rectangular plates. The actual plate was extended to make up an equivalent cyclic periodicity system and the plate elements become cyclic periodic elements, whereby the stiffness matrix become a cyclic matrix and the finite element matrix equation was uncoupled by using double U-transformation. This method can easily analyze the plate with arbitrarily distributed loads and the calculation is only performed for one element. The method has high computational efficiency and can quickly converge to exact solutions. The exact analytical finite element solution, the exact error expression and exact convergence rate are derived. These results can be not obtained if other methods are used instead. Numerical examples of rectangular plates with simply supported or clamped edges and a comparison with other methods show the advantages and practical importance of the U-transformation finite element method in engineering analysis.
Thermodynamic analysis and experimental verification of hydrogen production from dimethyl ether partial oxidation reforming
Song Lingjun, Li Xinghu
2008, 34(11): 1307-1310.
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Thermodynamic analysis was carried out for theoretical reaction of hydrogen produced from dimethyl ether(DME) partial oxidation reforming by using the element-potential method. The gas concentrations in the product gas were calculated under the constant-pressure and adiabatic condition as a function of air-to-DME ratio(0.5~4) and pressure(0.1~0.5MPa). The result proves that H2 concentration decreases with increasing of pressure. H2 concentration produces from DME partial oxidation reaction is the largest under atmosphere when air-to-DME ratio is about 3. The maximum is about 35%. By increasing air-to-DME ratio, H2 concentration increases firstly and then decreases, and CO concentration doesn-t changes obviously, and the concentration of CO2 and CH4 decreased respectively. Adiabatic temperature increases with increasing of air-to-DME ratio. At last, the experiment of hydrogen-rich gas produces from plasma reforming of DME is carried out on self-made equipments to verify the analysis, it proves that the concentration of H2,CO,CO2 and CH4 as a function of air-to-DME ratio analyzed by the element-potential method is almost in agreement with the experimental result.
Novel filter algorithm of space-borne GPS orbit determination
Wu Zhihua, Ding Yangbin, Shen Gongxun
2008, 34(11): 1311-1314.
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When conventional EKF (extended Kalman filtering) algorithm was used in LEO (low earth orbit satellite) orbit determination by space-borne GPS (global positioning system). It is difficult to know the initial value of system noise variance. Therefore, the novel filter algorithm of orbit determination was proposed. In the new algorithm, the methods of linearization at the prior filtering estimate value was adopted during the linearization process of the nonlinear equations, and the disturbing equations were obtained, and then the disturbing equations were introduced in conventional EKF. Apply the EKF and the modified algorithm in LEO orbit determination based on space-borne GPS respectively, the results show the modified algorithm can restrain filter divergence of conventional EKF caused by the large deflection of system noise variance in a certain extent, and has better robustness to the selecting of initial value of system noise variance.
Fast algorithm for airborne SAR range cell migration correction
Zhang Kunhui
2008, 34(11): 1315-1318.
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The range-Doppler algorithm is quite popular in airborne synthetic aperture radar (SAR) image formation. To reduce the excessive computation load associated with the pixel by pixel interpolation required in traditional range Doppler algorithm (RDA) to remove range cell migration (RCM), a fast and interpolation-free range cell migration correction(RCMC) technique which only involves operations of two FFTs and one complex multiplication was proposed. Based on the analysis of echo signal model, the constraint on attainable maximum swath with such a fast RCMC technique was derived, and the relation between this constraint and the imaging resolution was also given. The analysis was validated by simulation results. The theoretical analysis, simulation and SAR real data processing result show that this technique can reduce the computational burden dramatically with high enough precision, and is amenable to on-board real time processing.
Parametric design of variational-wall-thickness blade body based on discrete data
Yu Weiwei, Song Yuwang, Xi Ping
2008, 34(11): 1319-1322.
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A new method about parametric design of variational-wall-thickness blade body was provided, which could effectively solve the problem that how to modify the blade cross shape. It is convenient and effective to adjust the blade wall thickness, then to improve the blade performance. An effective method that how to acquire the mean curves was given and proved step by step, which could gain the real mean curves by using the geometric modeling function based on unigraphics (UG). It provides a technology route that realizes the parametric design of inner curves, and introduces a feasible plan to complete the work about parametric design of blade based on UG/OpenAPI; this route contains the thought of orient-object and the generative modeling style, and adopts undo-marks and the style of immediately recording the position of inner points. This developed module system can help users to dynamically modify the blade shape in real time.
Simple scheduling algorithm for delay guarantee in VOQ architecture switches
Zhang Fuyang, Xiong Qingxu
2008, 34(11): 1323-1326.
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Combining the earliest deadline first (EDF) policy and round robin manner, a simple scheduling algorithm was proposed to provide flow-based deterministic delay guarantee in virtual output queueing (VOQ) architecture switches.The EDF policy was employed to arbitrate the flow competitions in VOQ queues, and the round robin strategy was used to build input and output matching. In this case, the interval time between a packet arrival and that when it becomes the head cell in the VOQ, and the time from the packet becomes the head cell to it has been conveyed to the correspond output can be regard as the queuing time and service time in OQ architecture, respectively. The relation between the delay bounds and the packet inter-arrival times were derived. More important, the obtained results not only pave the way for design of more efficient algorithms, but also provide a novel approach to estimating that if there exist conflicts among the distinct delay bounds or not.
Fast region merging algorithm for watershed transform based on adjacency list
Li Suqi, Zhang Guangjun
2008, 34(11): 1327-1330.
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A fast region merging algorithm was proposed to solve the oversegmentation problem produced by the watershed transform for image segmentation. Firstly, the gradient image was preprocessed with Lee filter to reduce the oversegmentation initially. Then the region adjacency graph (RAG) with its adjacency list of data structure was used to represent the image partitions after the initial partitioning with the classical watershed transform. On the basis of the adjacency lists the region merging process followed a two-step threshold merging strategy in order to reduce the computation complexity. A hybrid region dissimilarity function was presented to measure the degree of similarity between two regions for the region merging. It combined the relative boundary integrity criteria and the boundary length criteria with the traditional region homogeneity criteria to increase the contour accuracy of merged regions. Experimental results show that this algorithm improves the region merging accuracy and processing speed greatly.
Adaptive fusion algorithm based on wavelet neural networks for multisensor measurement
Yuan Quan, Dong Chaoyang, Wang Qing
2008, 34(11): 1331-1334.
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To solve the problems of nonlinear and uncertain fusion systems, an adaptive fusion algorithm based on wavelet neural networks(WNNs) for multisensor measurement was proposed. The fusion system consisted of extended Kalman filters(EKFs), WNNs, knowledge base(KB) and track-to-track fusion algorithms. Based on the distributed fusion method, sensor precision values, sensor states and the local estimation errors were transferred from sensors to WNNs to deduce the relevant sensor confidence degrees in the real-time process of data fusion. In order to obtain the sensor confidence degrees, contextual information theory and normalized variable method were introduced to WNNs and the experimental data were implemented to train WNNs. According to the rules about the sensor confidence degrees, KB made decisions to select suitable track-to-track fusion algorithms. Simulation results show that the algorithm can effectively adjust the system to adapt contextual changes and has strong fusion capability in resisting uncertain information.
Method for estimating quality of infrared small target image
Diao Weihe, Mao Xia, Dong Xuyang
2008, 34(11): 1335-1338.
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A new criterion named interferential degree of background was proposed to estimate the quality of infrared small target image. It was described quantitatively by two indicators, one is ‘confusion degree of background upon target’ which represents the ability of the background providing false targets, the other is ‘shielding degree of background upon target’ which represents the ability of the background shielding the target. Experimental results show that the results estimated by this criterion are more consistent with the facts compared with traditional methods (SNR, signal to noise ratio), and they can provide more accurate information about the difficulty degree of detecting or recognizing the targets which is concerned by the researchers. Meanwhile, the criterion is valuable for quality estimation of small infrared target image which does not contain the information of the target.
Novel method of position determination for low earth orbiter micro-nano satellite based on nonlinear model predict filter
Zhong Huimin, Fang Jiancheng
2008, 34(11): 1339-1342.
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To solve two problems on micro-nano satellite that the dates of position and velocity is not consecutive for using global position system(GPS) individually and the errors of position and velocity radiate rapidly using orbital dynamics, a novel method of position determination for low earth orbiter( LEO) micro-nano satellite based on nonlinear model predict filter (MPF) was proposed. In this method,MPF predictd the errors of model which is because orbital dynamics modle is not precise as the first step of estimation, and the informations of GPS on satellite as observations, then combined with extended Kalman filter (EKF)which was improved to obtain the position and velocity not only consecutively but also precisely as GPS for single point position. Simulations show that, it is effectively to get position and velocity consecutively, and the pricition is better than EKF.
Service-oriented business process modeling language
Xing Shaomin, Zhou Bosheng, Chen Tianying
2008, 34(11): 1343-1348.
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Through analysis of the existing business process modeling languages, their lack of service-oriented support was indicated. A new service-oriented visual business process modeling language VPML-S was proposed based on the existing visual process modeling language (VPML). The conceptual design framework for VPML-S was proposed and its general modeling elements were outlined. The meta-model for VPML-S was designed by using UML class diagram, and its formal model was established on this basis. The service-oriented function provided by service element, the reuse mechanism between business processes provided by nested sub process element, the collaboration mechanism between business processes provided by pipeline element and the interoperability support mechanism between VPML-S business processes and business processes established by other languages were analyzed and evaluated. Visual icons replacement mechanism and meta-model expansion mechanism provided by VPML-S were discussed. Finally, an online shopping flow example was presented to demonstrate the efficiency of the VPML-S for business process reuse, collaboration and interoperability in service-oriented environment.
Polynomial regression modeling based on Gram-Schmidt process
Wang Huiwen, Guo Lijuan
2008, 34(11): 1349-1352.
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The polynomial regression model is a widely applied nonlinear regression method. Since the high correlation exists among independent variables in the polynomial regression model, it will induce excessive computational error to estimate coefficients with the ordinary least square regression. A method of polynomial regression modeling based on Gram-Schmidt process which can achieve the orthogonalization of the independent variables and overcome the adverse effects of multicollinearity to regression modeling was proposed, so as to apply ordinary least square to regression modeling effectively. The independent variables including notable explaining information can be selected effectively, at the same time redundant information is deleted. Simulation data analysis was adopted to test the effectiveness of the method.
Conductive error influence on temperature measurement
Cai Jing, Yang Yongjun, Liao Li, Wang Yi
2008, 34(11): 1353-1355.
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To study the conductive error of straight sensor, a special sensor was designed, which can measure 3 points- temperature, air flow, downside and upside of the bracket. The first and the third point were movable to meet the need of study. The theory model was set up and conductive correct coefficient formula was deducted. To avoid the influence of radiation error, a method of boot-heating was adopted to study the influence of Ma, bottom temperature and long-diameter ratio to conductive error, and useful datum were received. Conductive correct coefficient formula was applied to calculate conductive error of high-temperature-water-cooled harrow when the air flow velocity was low (Ma=0.1). The relative error was little than 10%. It pointed out that when considering the conductive error on temperature measurement, it is not comprehensive that whether long-diameter ratio is larger than 10 or not, bottom temperature is also an important thing.
Fast remote sensing image registration algorithm
Tian Yue, Zhang Yongmei, Li Bo
2008, 34(11): 1356-1359.
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Aiming at the registration of multi-sensor remote sensing images, a fast and effective image registration method was presented. Based on hierarchical candidate point set matching, the registration algorithm makes full use of the advantages of hierarchical matching and candidate point set matching approach, reduces feature extraction and searching space, and introduces distance calculation into the determination of homologous control point pairs, it can availably decide homologous control point pairs and decrease mismatching rate. The increased distance calculation has much lower time cost, and it does not change with the size of images. It is concerned with the number of final matched points in images. The effect of image registration algorithm was evaluated by subjective and objective method. Experiment results show the proposed algorithm can accurately register multi-spectral images and panchromatic images with some shift, rotation angles and background noises, and it can increase the speed and precision of registration.
Design method for surface of stretching tool for complex aircraft skin
Han Jinquan, Wan Min, Yuan Sheng, Xu Xudong
2008, 34(11): 1360-1363.
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A design method based on equilong section lines for tool surface in complex aircraft skin stretching was proposed to improve the strain distribution of blank during stretching, against the lack of practical and detailed design methods for tool surface in complex aircraft skin stretching. In this method, section lines of tool surface along stretching direction were designed as equilong as possible by adjustment of process addendum to gain approximate elongations on all section lines of blank after stretching, and then curvature and tangent directions were adjusted to obtain uniform strain distribution on blank after stretching and decrease or avoid appearance of failings relative strain distribution. This design method was verified to be of feasibility and validity by the design of a tool surface for a complex aircraft skin stretching and the strain distribution obtained by finite element method (FEM).
Two-level task partition scheduling design in integrated modular avionics
He Feng, Song Liru, Xiong Huagang
2008, 34(11): 1364-1368.
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To solve the real-time partition schedule problem in the integrated modular avionics, a two-level hierarchical schedule model was proposed in which the operation system adopts round-robin scheduling strategy and each individual partition adopts dynamic priority scheduling strategy. For the schedulablity analysis problem, the system consume time was calculated based on the task demand bound function by using round-robin time and partition task performance rate as the key parameters. From the calculated system consume time, the partition schedulable judging condition was obtained. The schedulablity calculation bound was also developed by observing the task each implementation with the releasing jitter. Through studying the relationship between the round length and the task periods, the maximum task load upper limit utilization were developed under the condition that the partition was schedulable. For the partition design problem, the partition scheduling key parameters analytical model was established. Then the partition designable judging condition was got. Finally, a practice example was given.

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