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利用计算机实现自动、准确的秀丽隐杆线虫(C.elegans)的各项形态学参数分析,至关重要的是从显微图像上分割出线虫体态,但由于显微镜下的图像噪声较多,线虫边缘像素与周围环境相似,而且线虫的体态具有鞭毛和其他附着物需要分离,多方面因素导致设计一个鲁棒性的C.elegans分割算法仍然面临着挑战。针对这些问题,提出了一种基于深度学习的线虫分割方法,通过训练掩模区域卷积神经网络(Mask R-CNN)学习线虫形态特征实现自动分割。首先,通过改进多级特征池化将高级语义特征与低级边缘特征融合,结合大幅度软最大损失(LMSL)损失算法改进损失计算;然后,改进非极大值抑制;最后,引入全连接融合分支等方法对分割结果进行进一步优化。实验结果表明,相比原始的Mask R-CNN,该方法平均精确率(AP)提升了4.3个百分点,平均交并比(mIOU)提升了4个百分点。表明所提出的深度学习分割方法能够有效提高分割准确率,在显微图像中更加精确地分割出线虫体。 相似文献
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Identifying change-prone sections of code can help managers plan and allocate maintenance effort. Design patterns have been used to study change-proneness and are widely believed to support certain kinds of changes, while inhibiting others.
Recently, several studies have analyzed recorded changes to classes playing design pattern roles and find that the patterns
“folklore” offers a reasonable explanation for the reality: certain pattern roles do seem to be less change-prone than others. We push this analysis on two fronts: first, we deploy W. Pree’s metapatterns, which group patterns purely by structure (rather than intent), and argue that metapatterns are a simpler model to explain
recent findings by Di Penta et al. (2008). Second, we study the effect of the size of the classes playing the design pattern and metapattern roles. We find that size explains more of the variance in change-proneness
than either design pattern or metapattern roles. We also find that both design pattern and metapattern roles were strong determinants
of size. We conclude, therefore, that size appears to be a stronger determinant of change-proneness than either design pattern
or metapattern roles, and observed differences in change-proneness between roles might be due to differences in the sizes
of the classes playing those roles. The size of a class can be found much more quickly, easily and accurately than its pattern-roles.
Thus, while identifying design pattern roles may be important for other reasons, as far as identifying change-prone classes,
sheer size might be a better indicator. 相似文献
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Touati Rabeb Messaoudi Imen Oueslati Afef Elloumi Lachiri Zied 《Multimedia Tools and Applications》2019,78(10):13047-13066
Multimedia Tools and Applications - The Helitrons, an important sub-class of the transposable elements (TEs) class II, have been revealed in diverse eukaryotic genomes. They are mobile elements... 相似文献
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介绍了以三星公司的S3C2410芯片为嵌入式处理器,以嵌入式Linux为操作系统的GPS车载导航系统的设计思想,对硬件的设计和操作系统内核的移植做了详细的说明,最后对G P S接收模块进行了设计。这样的系统设计,性价比高,在车载导航系统中有广泛的应用前景。 相似文献
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针对目前缺乏有效区分卖方信用增长类型的问题,提出了一种卖方交易数据转换的方法,并提出了C2C交易信用增长模式分类算法。通过引入监督的XYF网络方法对电子商务交易数据进行分析,能够对处于同一行业中、具有不同信用增长模式的卖方分类,为卖方的虚假信用识别提供了一种有效的途径,也为卖方的交易模式进行分类识别提供了一种新的思路。 相似文献
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The performance of intelligent electromyogram (EMG)-driven prostheses, functioning as artificial alternatives to missing limbs, is influenced by several dynamic factors including: electrode position shift, varying muscle contraction level, forearm orientation, and limb position. The impact of these factors on EMG pattern recognition has been previously studied in isolation, with the combined effect of these factors being understudied. However, it is likely that a combination of these factors influences the accuracy. We investigated the combined effect of two dynamic factors, namely, forearm orientation and muscle contraction levels, on the generalizability of the EMG pattern recognition. A number of recent time- and frequency-domain EMG features were utilized to study the EMG classification accuracy. Twelve intact-limbed and one bilateral transradial (below-elbow) amputee subject were recruited. They performed six classes of wrist and hand movements at three muscular contraction levels with three forearm orientations (nine conditions). Results indicate that a classifier trained by features that quantify the angle, rather than amplitude, of the muscle activation patterns perform better than other feature sets across different contraction levels and forearm orientations. In addition, a classifier trained with the EMG signals collected at multiple forearm orientations with medium muscular contractions can generalize well and achieve classification accuracies of up to 91%. Furthermore, inclusion of an accelerometer to monitor wrist movement further improved the EMG classification accuracy. The results indicate that the proposed methodology has the potential to improve robustness of myoelectric pattern recognition. 相似文献
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Kozorez D. A. Krasilshchikov M. N. Kruzhkov D. M. Sypalo K. I. 《Journal of Computer and Systems Sciences International》2015,54(5):798-807
Journal of Computer and Systems Sciences International - This paper is the first in a series of works devoted to the problems of a spacecraft in the geostationary orbit autonomous operation. The... 相似文献
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Microsystem Technologies - The aim of this study is to evaluate the elastic properties of high-density polyethylene (HDPE) using single-walled carbon nanotubes (SWCNTs) reinforcements with... 相似文献
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《Ergonomics》2012,55(11):1516-1527
AbstractMany occupations require both physical exertion and cognitive task performance. Knowledge of any interaction between physical demands and modalities of cognitive task information presentation can provide a basis for optimising performance. This study examined the effect of physical exertion and modality of information presentation on pattern recognition and navigation-related information processing. Results indicated males of equivalent high fitness, between the ages of 18 and 34, rely more on visual cues vs auditory or haptic for pattern recognition when exertion level is high. We found that navigation response time was shorter under low and medium exertion levels as compared to high intensity. Navigation accuracy was lower under high level exertion compared to medium and low levels. In general, findings indicated that use of the haptic modality for cognitive task cueing decreased accuracy in pattern recognition responses.Practitioner Summary: An examination was conducted on the effect of physical exertion and information presentation modality in pattern recognition and navigation. In occupations requiring information presentation to workers, who are simultaneously performing a physical task, the visual modality appears most effective under high level exertion while haptic cueing degrades performance. 相似文献
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通过树型菜单,用户可以对资源的结构、类型有直观的了解,但目前很多B/S系统的菜单还是通过代码生成的。为此,基于.NET技术,通过开源项目Peta Poco实现代码,设计并实现了动态导航菜单系统;介绍了数据库设计、算法思想。该技术避免了静态目录树下因数据源经常性改变而频繁修改程序代码的弊端,导航菜单通过数据库进行控制,提高了系统的安全性,使管理变得更加灵活、高效。 相似文献
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This study examines mental workload and performance in simulated high-speed ship navigation. Two navigation methods were compared based on an electronic chart display and information system (ECDIS) and a conventional system using paper charts. Twenty naval cadets navigated in high-fidelity simulators through a 50 nautical mile course with varying levels of difficulty. Results showed that ECDIS navigation significantly improved course-keeping performance, but reduced the total amount of communication on the bridge. No differences were observed in subjective workload between groups. Heart rate variability and skin conductance measurements indicated higher workload in conventional navigation, but the differences between groups were not significant. 相似文献
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将动态交通分配实施过程纳入预测控制框架下以满足实时交通诱导的目的,提出一种交通诱导预测控制算法.该算法是在滚动时域基础上进行的,包括实时交通分配、交通流模拟运行及评价以及进化最佳路径3 个重要环节.仿真结果表明,交通诱导预测控制是一种良好的计算机控制方法学,其优化过程预先考虑了目前交通分配对未来路网的影响,因而可有效地防范交通拥堵,实现考虑反馈的路网交通流实时分配优化,同时为出行者提供最佳路径. 相似文献
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ANDREAS DIEBERGER 《International journal of human-computer studies》1997,46(6):805-825
This paper discusses a navigation behavior on Internet information services, in particular the World Wide Web, which is characterized by pointing out information using various communication tools. We call this behaviorsocial navigationas it is based on communication and interaction with other users, be it through email, or any other means of communication. Social navigation phenomena are quite common although most current tools (like web browsers or email clients) offer very little support for it. We describe why social navigation is useful and how it can be supported better in future systems. We further describe two prototype systems that, although originally not designed explicitly as tools for social navigation, provide features that are typical for social navigation systems. One of these systems, the Juggler system, is a combination of a textual virtual environment and a web client. The other system is a prototype of a web-hotlist organizer, called Vortex. We use both systems to describe fundamental principles of social navigation systems. 相似文献
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A. P. Voiskovskii D. A. Kozorez M. N. Krasil’shchikov D. M. Kruzhkov K. I. Sypalo 《Journal of Computer and Systems Sciences International》2016,55(5):785-795
This study continues the series of papers devoted to the approach to solving the problem of autonomous navigation of a spacecraft (SC) in a geostationary orbit at all stages of its lifecycle: final ascent, transfer to the operating longitude, remaining at the operating longitude, removal from the orbit, and burial. In [1], we formulated the concept of autonomous navigation of a spacecraft at the stage of its final ascent to a geostationary orbit. This stage is most complicated from the technical point of view, taking into account the nonlinearity of the applied mathematical models, the influence of uncontrollable factors of various physical nature, and the necessity of the application of promising hardware (electric low-thrust engine, onboard receiver of signals from global navigation satellite systems, intersatellite communication channels, etc.). Taking this into account, the only constructive method for proving the viability and efficiency (taking into account the requirements formulated by the customer who placed the order) of the developed concept of the autonomous navigation at the final ascent stage in the mathematical simulation of this process. The subject of this study is to demonstrate the capabilities of the developed concept of autonomous navigation from the point of view of achieving the required level of reliability and accuracy in solving the navigation problem at the final ascent stage. This demonstration is based on the analysis of the results of imitating the simulation of the process of a spacecraft’s final ascent to a geostationary orbit obtained using the specially developed software complex. 相似文献
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基于雷达–扫描器/惯性导航系统的微小型无人机室内组合导航 总被引:2,自引:0,他引:2
本文提出一种基于雷达–扫描器/惯性导航系统(radar-scanner/INS)的微小型无人机室内导航方法.为提高算法的实时性,采用基于扩展卡尔曼滤波(EKF)的DC同步定位与构图技术(SLAM)实现定位和构图;在更新状态值的扫描匹配过程中提出启发性逻辑来筛选激光雷达数据,以提高算法对无人机因姿态和高度变化而引起的轮廓地图波动的抗干扰性;在特征匹配的过程中选取合理的地图轮廓特征,并利用扫描匹配的结果和特征匹配的传递性提出了精度较高的引导配对,以提高特征配对在三维环境下的准确性;最后,将DC SLAM与惯性导航系统进行基于EKF的组合滤波,给出无人机的全状态估计.通过与GPS/INS组合导航对比以及室内飞行验证,本文提出的方法能够满足无人机飞行控制对导航实时性和精度的要求. 相似文献