一种合并状态度量计算的高效并行Turbo码译码器结构设计及FPGA实现

为满足无线通信中高吞吐、低功耗的要求,并行译码器的结构设计得到了广泛的关注。基于并行Turbo码译码算法,研究了前后向度量计算中的对称性,提出了一种基于前后向合并计算的高效并行Turbo码译码器结构设计方案,并进行现场可编程门阵列(field-programmable gate array,FPGA)实现。结果表明,与已有的并行Turbo码译码器结构相比,本文提出的设计结构使状态度量计算模块的逻辑资源降低50%左右,动态功耗在125 MHz频率下降低5.26%,同时译码性能与并行算法的译码性能接近。

小龙虾识别与度量关键技术研究与应用

小龙虾的表型性状是水产养殖和遗传育种中非常重要的经济依据,为了精准实现对小龙虾的视觉检测与定位,并对其主体躯干表型特征进行测量。首先提出了一种基于Mask RCNN实例分割模型检测小龙虾的方法,不仅能快速识别小龙虾,还能对其进行实例分割,生成高质量的二值掩膜图。然后在此基础上,提出一种新的小龙虾度量算法:通过提取小龙虾的轮廓曲线,获取其中轴线,采用分区法提取小龙虾的特征区域,再利用凸包和凸包缺陷算法获取小龙虾的特征点,实现对其全长、体长、头胸甲、腹部、尾扇等主要部位的无接触度量计算。结果表明:Mask RCNN模型在小龙虾数据集上具有很好的泛化性能,模型分割准确率达到了94.6%,目标识别的平均检测精度达到了98.7%。各测量指标的平均绝对误差均在5 mm之内,比人工手动测量难度大大减小,并且稳定高效,重复性更好。该方法将有利于生产和选育过程中小龙虾的鉴别及结构尺寸的快速获取。

计算机系统变革性研究的4个问题

进入21世纪,计算机科学与技术领域正在面临一次深刻的变革,计算机系统子领域也不例外.指出这次变革的一个主要特征是从"人机共生"跃变到"人机物社会".这个跃变也为计算机系统的研究提出了4个带有基础性的挑战:1)重新审视计算和计算机系统概念,以及刻画新型负载和使用模式;2)研究新型的计算机系统度量;3)让计算机系统直接支持网络;4)发现和利用涌现现象.基于中国科学院计算技术研究所织女星网格小组和国际同行的研究工作,讨论了这4个问题,并指出这些问题还没有答案,这提供了很多研究机会.

基于EMD的剖分空间关系计算模型初探

针对在空间关系计算中存在的经纬度坐标缺少区域信息的问题,以及基于影像直接进行空间关系计算中存在的计算复杂的问题,利用具有点面二相性的基于地图分幅的扩展模型(EMD)全球剖分面片作为空间关系计算的基本单位,采用EMD全球剖分面片编码代替经纬度坐标进行空间关系计算,提出EMD剖分空间关系计算模型的体系架构,并在此基础上进行验证实验,证实了该模型的可行性。

基于复杂网络的软件复杂性度量的研究

随着计算机科学技术的不断发展,软件的规模性和复杂性不断的扩大,随之带来的问题是传统的度量方法和对软件的开发控制不能满足日益发展的计算机科学技术的发展。在这个问题上,我国的研发人员付出了很大的努力,去发现新的方法对软件测量的使用,从而控制软件的质量,优化软件的结构,使软件的开发有利于计算机科学技术的发展。

通信行业标准中软件运维非功能性工作量评估方法研究

本文对信息化项目中软件开发投入运营后运维部分的投资估算标准方法的相关研究。通过研究现有信息化项目涉及的国家标准、地方标准、团体标准等标准,结合软件开发需求单位、用户维度痛点以及分析实际软件开发运维工作涉及的系统、运维工作内容等相关数据,提出相应的估算标准方法。为信息化项目软件运维非功能性相关工作量的投资估算提供较为清晰、准确的方法。

CMDC:一种差异互补的迭代式多维度文本聚类算法

针对传统多维度文本聚类算法把文本表示与聚类过程分离,忽略了维度间的互补特性的问题,提出了一种差异互补的迭代式多维度文本聚类算法——CMDC,实现文本聚类与特征调整过程的统一优化。CMDC算法挑选维度聚类间结果的互补文本,基于局部度量学习算法利用互补文本促进聚类的特征调优,以维度的度量一致性来解决多维度文本聚类的划分一致性。实验结果表明,CMDC算法有效地提升了多维度聚类性能。

Theoretical Calculation of Nitrogen Q-Branch CARS Spectra

The coherent anti Stokes Raman spectrum (CARS) technology, as a new temperature measurement method, is paid more and more attention to recently. The theoretical CARS spectra of nitrogen Q branch are calculated, the spectra at different temperatures are obtained and the effect on the CARS spectra of Raman line width is also discussed. The results show that CARS spectra are sensitive to temperature and spectrum solution is good when the Raman line width is narrow enough. The accuracy of detonation temperature measurement with this technology will reach high level.

Similarity measure design and similarity computation for discrete fuzzy data

The similarity computations for fuzzy membership function pairs were carried out.Fuzzy number related knowledge was introduced,and conventional similarity was compared with distance based similarity measure.The usefulness of the proposed similarity measure was verified.The results show that the proposed similarity measure could be applied to ordinary fuzzy membership functions,though it was not easy to design.Through conventional results on the calculation of similarity for fuzzy membership pair,fuzzy membership-crisp pair and crisp-crisp pair were carried out.The proposed distance based similarity measure represented rational performance with the heuristic point of view.Furthermore,troublesome in fuzzy number based similarity measure for abnormal universe of discourse case was discussed.Finally,the similarity measure computation for various membership function pairs was discussed with other conventional results.

Practical network coding-aware routing protocol for multi-hop wireless networks

Network coding has been considered as one of the effective strategies that improve the throughput of multi- hop wireless networks. In order to effectively apply network coding techniques to the real multi-hop wireless networks, a practical network coding aware routing protocol is proposed in this paper, for unicast sessions in multi- hop wireless networks. The protocol is based on a novel routing metric design that captures the characteristics of network coding and unicast sessions. To ensure the novel routing mettle can operate with practical and widely available path calculation algorithms, a unique mapping process is used to map a real wireless network to a virtual network. The mapping process ensures that the paths with the biggest coding opportunities will be selected by commonly used path calculation algorithms. Simulation results show that the proposed routing protocol is effective to improve the network throughput.

High Accuracy Calculation for Excited-State Energies of H Atoms in a Magnetic Field

Using the recently developed finite-basis-set method with B splines, excited states of H atoms in a magnetic field have been calculated. Energy levels are presented for the ten excited states, 2so, 3d＇0, 3po, 3p-1, 3d_1, 4d-1, 3d-2, 4d-2, 4f-2 , and 5f-2 as a function of magnetic field strengths with a range from zero up to 2.35 × 10^6 T. The obtained results are compared with available high accuracy theoretical data reported in the literature and found to be in excellent agreement. The comparison also shows that the current method can produce energy levels with an accuracy higher than the existing high accuracy method [Phys. Rev. A 54 （1996） 287]. Here high accuracy energy levels are for the first time reported for the 3d＇0, 4d-1, 4d-2, 4f-2, and 5f-2 states.

Image Distortion Metric Based on Total Bounded Variation

Image definition measurement plays an important role in various image processing applications.And a reliable objective image definition metrics is critical for evaluating the definition of the restored image.In this paper,a novel image distortion metric based on minimal Total Bounded Variation(TBV) is presented.It is clarified that when the restored image approximates to the original clear image,the smaller the TBV is,the better the definition of the restored image is.Furthermore,the difference between the restored image and the original clear image is the smallest when the TBV is minimum.In numerical results,the TBV of the original clear image,blur image and restored image are presented and compared,and the results demonstrate the validity of the distortion metric proposed.

A New Calculation of the In-Medium Quark Condensate at Finite Density and Temperature

The in-medium quark condensate is studied with an equivalent-mass approach in which one does not need to make assumptions on the derivatives of model parameters with respect to the quark current mass.It is shown that the condensate is generally a decreasing function of both the density and temperature with the decreasing speed depending on the confinement parameter.Specially,at given density,the condensate decreases on increasing temperature.The decreasing speed is comparatively small at lower temperature,and becomes very fast at higher temperature.

The Calculations of Propeller Induced Velocity by RANS and Momentum Theory

In order to provide instructions for the calculation of the propeller induced velocity in the study of the hull-propeller interaction using the body force approach,three methods were used to calculate the propeller induced velocity：1） Reynolds-Averaged Navier-Stokes（RANS） simulation of the self-propulsion test,2） RANS simulation of the propeller open water test,and 3） momentum theory of the propeller.The results from the first two methods were validated against experimental data to assess the accuracy of the computed flow field.The thrust identity method was adopted to obtain the advance velocity,which was then used to derive the propeller induced velocity from the total velocity field.The results computed by the first two approaches were close,while those from the momentum theory were significantly overestimated.The presented results could prove to be useful for further calculations of self-propulsion using the body force approach.

Abundance quantification by independent component analysis of hyperspectral imagery for oil spill coverage calculation

The estimation of oil spill coverage is an important part of monitoring of oil spills at sea.The spatial resolution of images collected by airborne hyper-spectral remote sensing limits both the detection of oil spills and the accuracy of estimates of their size.We consider at-sea oil spills with zonal distribution in this paper and improve the traditional independent component analysis algorithm.For each independent component we added two constraint conditions:non-negativity and constant sum.We use priority weighting by higher-order statistics,and then the spectral angle match method to overcome the order nondeterminacy.By these steps,endmembers can be extracted and abundance quantified simultaneously.To examine the coverage of a real oil spill and correct our estimate,a simulation experiment and a real experiment were designed using the algorithm described above.The result indicated that,for the simulation data,the abundance estimation error is 2.52% and minimum root mean square error of the reconstructed image is 0.030 6.We estimated the oil spill rate and area based on eight hyper-spectral remote sensing images collected by an airborne survey of Shandong Changdao in 2011.The total oil spill area was 0.224 km^2,and the oil spill rate was 22.89%.The method we demonstrate in this paper can be used for the automatic monitoring of oil spill coverage rates.It also allows the accurate estimation of the oil spill area.

Calculation of Measurement Uncertainty for Stiffness Modulus of Asphalt Mixture

Asphalt mixture is a highly heterogeneous material, which is one of the reasons for high measurements uncertainty when subjected to tests. The results of such tests are often unreliable, which may lead to making bad professional judgments. They can be avoided by carrying out reliable analyses of measurement uncertainty adequate for the research methods used and conducted before the actual research is done. This paper presents the calculation of measurements uncertainty using as an example--the determination of the stiffness modulus of the asphalt mixture, which, in turn, was accomplished using the indirect tension method. The paper also shows the employment of the basic methods of statistical analysis, such as testing two mean values and conformity tests. Essential concepts in measurements uncertainty have been compiled and the determination of the stiffness module parameters are discussed. It has been demonstrated that the biggest source of error in the stiffness modulus measuring process is the displacement measure. The aim of the research was to find the measurement uncertainty for stiffness modulus by an indirect tensile test and the presentation of examples of the used statistical methods.

Short-Time Decoherence of Solid-State Qubit at Optimal Operation Points

We investigate the short-time decoherence of a solid-state qubit under Ohmic noise at optimal operation points. The decoherence is analyzed by maximum norm of the deviation density operator. It is shown that at the temperature T = 3 mK, the loss of the fidelity due to decoherence is much smaller than the DiVincenzo low decoherence criterion, which means that the mode/may be an optimal candidate of qubit for quantum computation.

The rough representation and measurement of quotient structure in algebraic quotient space model

Granular computing is a very hot research field in recent years. In our previous work an algebraic quotient space model was proposed,where the quotient structure could not be deduced if the granulation was based on an equivalence relation. In this paper,definitions were given and formulas of the lower quotient congruence and upper quotient congruence were calculated to roughly represent the quotient structure. Then the accuracy and roughness were defined to measure the quotient structure in quantification. Finally,a numerical example was given to demonstrate that the rough representation and measuring methods are efficient and applicable. The work has greatly enriched the algebraic quotient space model and granular computing theory.

Relationship between oceanic heat content and sea surface height on interannual time scale

The relationship between heat content and the interannual time scale is examined with satellite sea surface height （SSH） in the global ocean on altimeter measurements, historical hydrography, and model assimilation outputs. Results show that correlation between altimetric SSH and heat content in the upper 700 m calculated from Ishii data is geographically nonuniform. In the tropical ocean, heat content and SSH are strongly correlated and exhibit nearly the same interannual variations. In the polar ocean, their correlation is relatively weak. Further analysis with Simple Ocean Data Assimilation outputs shows that such nonuniform distribution is not from dynamical origin but from the limited integral depth selected to calculate heat content. The integral depth of 700 m is inadequate to capture variation of the deep main thermocline in the polar region. The halosteric effect also contributes to the nonuniform pattern of correlation, because saline contraction becomes significant in the polar ocean owing to low temperature.