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1.
A logistic map controlled secure arithmetic coding is proposed, the Logistic map is used to control the order of the symbols in the model and change the probabilities of the symbols, which is applied to the image encryption. The proposed scheme makes the image transmit more secure and comfortably on the Internet, and that is done at little expense in terms of coding efficiency. In the coding process, it ensures the uniformity of the model being changed by the chaotic sequence, thus to meet the security requirements of image compression. The algorithm can be applied to any arithmetic codec based on multimedia data including video, image and audio. Its most strength compared with other cipher mode is that, there is a significant reduction in the redundancy of information during the compression process, and it is robust when attempting to estimate the information of the image and discovering the key. The scheme can effectively resist differential analyses from both cryptography and coding. 相似文献
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Adaptive clonal competition algorithm and its application in automatic electroplating production line scheduling 下载免费PDF全文
Aiming at small batch and multi-type electroplating production scheduling system with flexible process, an adaptive clonal competition algorithm(ACCA)is proposed. The capability of searching the global optimal value and the local optimal value of the new algorithm can be adjusted through the function between the cloning and mutation probability and the number of iterations. Besides, the population diversity of the adaptive clonal competition algorithm can be ensured through the competition mechanism, the elite migration mechanism and the raising new members mechanism. Compared with traditional clonal selection algorithm, adaptive clonal competition algorithm has higher searching ability and faster convergence speed. 相似文献
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Improved algorithms of modal parameter identification and its application to shaking table frame model test 下载免费PDF全文
Based on the data-driven stochastic subspace identification (SSI), an improved ITD method, an improved STD method and an improved complex index method are put forward. SSI has high identification accuracy, and Hankel matrix orthogonal projection calculation of data can retain all the useful information in the original data and simultaneously remove noise. The data obtained in P-matrix is taken as input for the ITD , STD and complex index methods, and then the three methods would no longer need random decrement technique or NExt method for pre-processing, thereby eliminating the error caused by the two pretreatment methods.The improved methods are applied to the modal parameter identification for structure shaking table test model by using the simulated earthquake response data from Tongji University. The recognition results further prove the correctness and feasibility of the improved methods. 相似文献
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Maria Filomena Carneiro 《Euphytica》1997,96(1):167-172
The most important advances obtained on in vitro coffee regeneration systems and in coffee genetic transformation, drawing
perspectives and scopes to further studies in these fields are presented and discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
5.
A product ontology screening method which can be used in variant design is proposed. With the support of complete ontology view of product resources, the product functional requirement and structural characteristics are converted to demand constraints, which are used to screen product ontology. For different screening hierarchies and objects, different screening rules such as pattern matching, case matching combined with manual decision and auto matching on the basis of case-based reasoning are adopted. The semi-automatic screening method with human-computer cooperation has impressive effectiveness on the improvements of the accuracy of design schemes and the flexibility and efficiency of design process. Finally, a variant design supporting system for building door and window is developed, which proves the feasibility and effectiveness of the method. 相似文献
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A clogging segment mechanical model is established on gas extraction horizontal borehole. Based on the air pressure extremes pmax of the construction site, we solve the corresponding critical clogging length L0 and find clogging will occur when L> L0. With the clogging segment mechanical model, we analyze the calculation method of the retreat drilling rod resistance in borehole. The influence rule of clogging length and air supplying system pressure on retreat drilling rod resistance is analyzed. Analysis results show that the main reason for difficult drilling clogging and retreat drilling rod is the higher pressure in borehole clogging segment. The retreat drilling rod resistance is especially sensitive to the change of air supplying system; therefore, the effective method of reducing the retreat drilling rod resistance is reducing the air supplying system pressure in borehole. The drilling construction status in Jiulishan coal mine is analyzed by using the clogging segment mechanical model, and three technical measures are put forward, including increasing slagging space, reducing slagging resistance and increasing drilling rod strength. When the improving measures are adopted, the pipe-sticking phenomena decreases, the drilling rod broken phenomenon are averted and the drilling efficiency increases by 17%. 相似文献
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Monitoring and detection of invasive alien plant species are necessary for effective management and control measures. Although efforts have been made to detect alien trees using satellite images, the detection of alien herbaceous species has been difficult. In this study, we examined the possibility of detecting non-native plants using deep learning on images captured by two action cameras. We created a model for each camera using the chopped picture method. The models were able to detect the alien plant Solidago altissima (tall goldenrod) and obtained an average accuracy of 89%. This study proved that it is possible to automatically detect exotic plants using inexpensive action cameras through deep learning. This advancement suggests that, in the future, citizen science may be useful for conducting distribution surveys of alien plants in a wide area at a low cost. 相似文献
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生物实验流程管理是生物实验室信息管理系统的核心,我们针对生物实验室实验流程灵活,数据流网络复杂等特点,设计了一套生物实验流程管理模型(Biological experiments flow management model,简称BioEFM),为生物实验室信息管理系统软件(Biology Laboratory Information Management System Software,缩写为BioLIMS)的开发提供了理论基础,大大提高了BioLIMS的开发效率。在此基础上开发的生物实验室信息管理系统软件(BioLIMS)应用于水稻基因组测序实验的信息管理中,为水稻基因组测序实验提供了灵活、便捷、高效的实验信息管理工具,为水稻基因组测序及后续的生物信息学分析奠定了良好的基础。 相似文献
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An Improved Learning Algorithm for BP Model and its Application to Load Forecasting in Power Systems
This paper analyses the cause of very slow learning rate during the time of ap-proaching the minim um poi nt in con vertional BP algorithm, by introducing weight factor into themodification of the connection weight,an improved leavning algorithm for BP model is presented,itcan sign ificantly in crease the learning rate and improve con vergent behaviour.As an illustrative ap-plication example,the n umeriCal resu It of the medium-term load forecasting is given. 相似文献
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Simplified culture method of detached ears and its application to vernalization in wheat 总被引:3,自引:0,他引:3
Summary The effects of the addition of sulfurous acid into culture solution and of cold treatment of the solution were examined to simplify the culture of detached wheat ears. In the simplified method, detached ears could be cultured at room temperature on the liquid medium containing 100 g/l sucrose and 0.075% sulfurous acid without any sterilization. The immature seeds in detached ears cultured by this method were treated with low temperature or with chemicals known to have vernalizing effect. The chemical treatment did not affect the chilling requirement of immature embryos, although photoperiodic response and narrow-sense earliness were reduced by kinetin and trypsin. The low temperature treatment drastically affected the chilling requirement, and fully vernalized mature seeds having normal germinability were obtained by treating the detached ears in culture with low temperature from 10 days after anthesis. 相似文献
13.
Traditional mineral resource visualized dynamic estimation and its application in 3D geological space 总被引:1,自引:0,他引:1
A new method for traditional mineral resource visualized dynamic estimation in 3D geological space is proposed, which is adaptive to the characteristics of resource exploitation and reserve classification in China. The method follows the daily workflow of mine exploitation, improves the traditional method for resource estimation by 3D visualization technologies, and replaces abstract regular geometries with real 3D geological models. Thus, the traditional method for resource estimation realizes visualization in the whole workflow of mine exploitation. The application results to some real mines show the estimation results are mainly affected by the spatial location, shape and thickness of mineral blocks and goaf. If the resource dynamic estimation is carried out by constructing 3D mineral models in consistent with real exploitation project, the accuracy of the traditional method can be effectively improved. 相似文献
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Inter simple sequence repeat (ISSR) polymorphism and its application in plant breeding 总被引:46,自引:0,他引:46
Inter simple sequence repeat (ISSR)-PCR is a technique, which involvesthe use of microsatellite sequences as primers in a polymerase chainreaction to generate multilocus markers. It is a simple and quick methodthat combines most of the advantages of microsatellites (SSRs) andamplified fragment length polymorphism (AFLP) to the universality ofrandom amplified polymorphic DNA (RAPD). ISSR markers are highlypolymorphic and are useful in studies on genetic diversity, phylogeny, genetagging, genome mapping and evolutionary biology. This review providesan overview of the details of the technique and its application in geneticsand plant breeding in a wide range of crop plants. 相似文献
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Composite gaussian process regression model and its application to prediction of silicon content in hot metal 总被引:1,自引:0,他引:1
In order to increase the predictive precision of gaussian process regression based soft sensor, a composite gaussian process regression model is proposed. This model combines the outputs of several gaussian process models as the output according to the variances and the distribution of the outputs, which results in higher prediction accuracy and higher robustness than the single gaussian process model. The proposed composite gaussian process regression model is successfully applied to the prediction of silicon content in hot metal. 相似文献
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疏浚淤泥这种超软土地基目前主要采用排水固结法进行加固,然而,工程实践发现,淤堵是一个重要的问题,新型防淤堵材料和施工工艺是研究的热点。依托恒大海南海花岛真空预压处理工程,引入一种应用于超软土地基处理的新型防淤堵真空预压法。该方法是直排式真空预压方法的进一步改进,将防淤堵排水板取代传统排水板,在连接方式上,将无孔钢丝软管取代了水平波纹管,也将传统的包扎捆绑改进成了三通密封接头,枪钉固定。结合施工动态监测和加固后检测,表明了该方法的加固效果和实用性。在此基础上,结合已有的室内模型试验研究,阐述其抽真空过程中在排水板附近防淤堵的原理和改善机制。 相似文献
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In order to improve the prediction performance of single model based soft sensor, the features of the current model combination frameworksby analynizing, a new multi model combination framework based on the bayesian model comparison is proposed. In this framework, fuzzy c means clustering to the historial data is used to analyze the production states, then the prediction performance of sub models at different states are compared based on bayesian model comparison. The comparing results are the basis of the model combination stratery at different states. With adapting cross validation predictive distribution, the samples got from the trained models are used to successfully reduce computation load of model comparion.The framework has obtained good results in the practical application. 相似文献
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针对低渗高突煤层煤巷条带预抽区域瓦斯治理难题,运用弹性力学理论,结合高压水动力特性,提出穿层钻孔煤巷条带水力压裂防突技术,建立计算目标煤层起裂压力计算模型,集成配套井下压裂成套设备,并进行工业性试验。试验结果表明:技术实施后,压裂钻孔的瓦斯抽采浓度和抽采纯量曲线呈现“高—低—高”特点,体现了压裂改造的双重作用;相比于水力割缝孔和普通穿层孔,压裂孔的瓦斯抽采纯量分别提高了20倍和133倍;预掘煤巷处的残余瓦斯含量降到8 m 3/t以下,穿层钻孔煤巷条带水力压裂增透技术消突效果显著。 相似文献
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枸杞树不同器官氮磷钾吸收规律及其合理施肥初探 总被引:1,自引:0,他引:1
为探明枸杞不同器官氮磷钾养分吸收规律,并提出合理的化肥用量,以7年生成龄和4年生幼龄‘宁杞1号’枸杞树为研究对象,利用田间试验研究枸杞年生育期内果实、枝条、叶片中氮磷钾养分含量变化动态,探讨枸杞干鲜果产量及氮磷钾累积动态,提出氮磷钾肥的推荐量。结果表明,枸杞果实、枝条和叶片中养分含量都为N>K>P。枝条中全氮、全钾含量呈双峰“M”型变化,叶片中全氮含量动态呈倒“V”型。各器官中氮、钾含量变异较大,而磷含量变幅较小。枸杞夏果、秋果期干鲜果产量及干果氮磷钾累积动态都呈抛物线型变化,7月和10月中旬为果实养分累积高峰期。枸杞干果产量与氮、磷、钾施肥量都服从二次曲线关系,幼龄枸杞树化肥推荐量分别为N 431~510 kg/hm2、P2O5 239~282 kg/hm2、K2O 362~379 kg/hm2。氮和钾是枸杞树各器官重要的营养元素,应在养分需求高峰期施肥补充树体的养分供应。 相似文献
20.
Dynamics of nitrogen and phosphorus in paddy field under deep application condition of urea pill and its pollution-reducing potential 总被引:2,自引:0,他引:2
Dynamics of the pollutants such as nitrogen, phosphorus and the suspended particulates in the field water and soil and its pollution-reducing potential are investigated in the rice plant returning-green stage using deep application technique of urea pill with the application depth of 3, 7 and 11 cm (expressed as t-3, t-7 and t-11, respectively) based on the micro-zone simulation field experiments. Results show that nitrogen content in the field water gradually decreases within 5~7 d after deep allocation of urea, and reaches the low level after the seventh day. NO-3-N concentration is higher than NH+4-N, but there is little difference between treatments. As the pollution source is concerned, NO-3-N in the field water should be considered. There isn’t any correlation between nitrogen content in the water and urea application depth in the field. By contrast with blank treatment(expressed as t-c), NO-3-N, NH+4-N and TN contents in the field water with deep application of urea pill decrease 29%~47%, 64%~89% and 79%~97%, respectively. The TP and DP are in the high level in the field water with t-3 and t-7. The TP, DP and SS concentration in the field water with t-11 decrease 32%~73%, 92%~99% and 50%~80%, suggesting that deep application of urea pill into 11 cm layer of the field should have a significant pollution-reducing potential and become one of effective measures to control non-point source pollution of agricultural system. 相似文献