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1.
纪腾其  孟军  赵思远  胡鹤还 《计算机应用》2021,41(12):3614-3619
长链非编码RNA(lncRNA)中的小开放阅读框(sORFs)能够编码长度不超过100个氨基酸的短肽。针对短肽预测研究中lncRNA中的sORFs特征不鲜明且高可信度数据尚不充分的问题,提出一种基于表示学习的深度森林(DF)模型。首先,使用常规lncRNA特征提取方法对sORFs进行编码;其次,通过自编码器(AE)进行表示学习来获得输入数据的高效表示;最后,训练DF模型实现对lncRNA编码短肽的预测。实验结果表明,该模型在拟南芥数据集上能够达到92.08%的准确率,高于传统机器学习模型、深度学习模型以及组合模型,且具有较好的稳定性;此外,在大豆与玉米数据集上进行的模型测试中,该模型的准确率分别能达到78.16%和74.92%,验证了所提模型良好的泛化能力。  相似文献   
2.
刘国源  万光海  庞柳  李智 《计算机科学》2014,41(11):137-140,168
问题框架(Problem Frames,PF)已经得到需求工程界的广泛重视和研究。目前,问题框架在理论基础和开发方法等方面已经有很多研究成果,但如何把它们应用到实际的软件开发项目中仍是一个有待解决的问题。本工具可帮助系统分析员实现从用户需求到软件规约的平滑和可推理的变换,从而为软件开发项目中需求的沟通、建模及分析等提供技术支持。此外,该工具产生的结果也为下一步的软件设计提供帮助。它对促进问题框架方法的进一步发展和成熟,如从研究走向实用,具有重要的推动作用。  相似文献   
3.
In this paper, we present a new approach for the progressive compression of three‐dimensional (3D) mesh geometry using redundant frame dictionaries and sparse approximation techniques. We construct the proposed frames from redundant linear combinations of the eigenvectors of a combinatorial mesh Laplacian matrix. We achieve a sparse synthesis of the mesh geometry by selecting atoms from a frame using matching pursuit. Experimental results show that the resulting rate‐distortion performance compares favorably with other progressive mesh compression algorithms in the same category, even when a very simple, sub‐optimal encoding strategy is used for the transmitted data. The proposed frames also have the desirable property of being able to be applied directly to a manifold mesh having arbitrary topology and connectivity types; thus, no initial remeshing is required and the original mesh connectivity is preserved.  相似文献   
4.
压缩采样中测量矩阵对于信号的压缩及重建都有着十分重要的作用。为了减小测量矩阵与稀疏变换矩阵的互相干性,对测量矩阵和稀疏变换矩阵的乘积,构造其Gram矩阵并通过最优投影法优化之。格拉斯曼框架各元素间具有较小的相干性,使优化后的矩阵逼近格拉斯曼框架则可以获得更好的性能。  相似文献   
5.
The free vibration analysis of asymmetrical three-dimensional (3D) uniform shear beam-columns with generalized boundary conditions (semirigid flexural and torsional restraints, lateral bracings, and lumped masses at both ends) subjected to an eccentric end axial load in addition to a linearly distributed eccentric axial load along its span is presented in a classic manner. The five coupled governing equations of dynamic equilibrium (i.e., two shear equations, two bending moment equations, and the pure torsion moment equation) are sufficient to determine the natural frequencies and modal shapes. The proposed model which is an extension of a 2D model presented previously by the writer includes the simultaneous 3D coupling effects among the lateral deflections, deformations of the cross section along the member (shear, torsional and rotational), the translational, rotational and torsional inertias of all masses considered, an eccentric end axial load in addition to a linearly distributed axial load along its span, and the end restraints. Deformations caused by shear forces and pure torsion are considered. The effects of axial deformations, warping torsion and torsional stability are not included. The proposed model shows that the dynamic behavior of 3D shear beam-columns is highly sensitive to the coupling effects just mentioned, particularly in members with both ends free to rotate. Analytical results indicate that except for doubly symmetric members with concentric axial loads and with perfectly clamped ends, the natural frequencies and modal shapes of 3D shear beam-columns are determined from the eigenvalues of a full 8×8 matrix, rather than from the uncoupled equations of transverse (or shear-wave equations) and torsional moment equilibrium. Two comprehensive examples are presented that show the effectiveness of the proposed method.  相似文献   
6.
This paper summarizes the findings of an experimental study to characterize the cyclic racking and monotonic loading performance of wood-stud and steel-stud wall specimens, which were sheathed on both faces with gypsum wall board (GWB). Some specimens were finished with joint compound at the GWB joints and over screw heads. The study provided data on monotonic and cyclic hysteresis load-displacement relationships. Based on the visual inspection of the specimens during the tests, several aspects of the failure modes were noted. Shear-load capacity and drift capacities were determined based on the envelope curves of the hysteresis cycles. A comparison of the envelope curves for steel-stud and wood-stud specimens provided insight as to the relative behaviors of the two wall system types, including capacity, measures of ductility, and energy dissipation. Finally, the study provided better understanding of the effects of finishing GWB joints on the shear capacity of the wall systems.  相似文献   
7.
本文对门式刚架轻型房屋钢结构的荷载取值、结构设计和计算、优化设计中应引起重视的问题做一定的分析、探讨,供设计同行参考。  相似文献   
8.
In this paper, we study the progressive collapse of three-dimensional framed structures made of reinforced concrete after the sudden loss of a column. The structures are represented by elastoplastic Euler-Bernoulli beams with elongation-rotation failure threshold. We performed simulations using the discrete element method considering inelastic collisions between the structural elements. The results show what collapse initiation and impact-driven propagation mechanisms are activated in structures with different geometric and mechanical features. Namely, we investigate the influence of the cross sectional size and reinforcement α and of the plastic capacity β of the structural elements. We also study the final collapse extent and the fragment size distribution and their relation to α, β, and to the observed collapse mechanisms. Finally, we compare the damage response of structures with symmetric and asymmetric reinforcement in the beams.  相似文献   
9.
Nature has provided inspiration for most of the man-made technologies. Scientists believe that dolphins are the second to humans in smartness and intelligence. Echolocation is the biological sonar used by dolphins and several kinds of other animals for navigation and hunting in various environments. This ability of dolphins is mimicked in this paper to develop a new optimization method. There are different meta-heuristic optimization methods, but in most of these algorithms parameter tuning takes a considerable time of the user, persuading the scientists to develop ideas to improve these methods. Studies have shown that meta-heuristic algorithms have certain governing rules and knowing these rules helps to get better results. Dolphin echolocation takes advantages of these rules and outperforms many existing optimization methods, while it has few parameters to be set. The new approach leads to excellent results with low computational efforts.  相似文献   
10.
阐述了使用CATIA软件建立加强框、梁类零件数字化模型的有效方法.率先采用法则(Law)、样条线(Spline)和平行曲线(Parellel)等方法精确定义出了均匀变化、曲率连续的内外缘条厚度,并对缘条、腹板、筋条的统一建模方法进行了研究与分析;尝试规范了精确、简练和快速的加强框、梁类零件数字化定义流程,从而解决了长期困扰飞机结构设计师的加强框、梁等结构件的建模问题.  相似文献   
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