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A splicing algorithm for best subset selection in sliced inverse regression
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作者 Borui Tang Jin Zhu +1 位作者 Tingyin Wang Junxian Zhu 《中国科学技术大学学报》 北大核心 2025年第5期22-34,21,I0001,共15页
In this study,we examine the problem of sliced inverse regression(SIR),a widely used method for sufficient dimension reduction(SDR).It was designed to find reduced-dimensional versions of multivariate predictors by re... In this study,we examine the problem of sliced inverse regression(SIR),a widely used method for sufficient dimension reduction(SDR).It was designed to find reduced-dimensional versions of multivariate predictors by replacing them with a minimally adequate collection of their linear combinations without loss of information.Recently,regularization methods have been proposed in SIR to incorporate a sparse structure of predictors for better interpretability.However,existing methods consider convex relaxation to bypass the sparsity constraint,which may not lead to the best subset,and particularly tends to include irrelevant variables when predictors are correlated.In this study,we approach sparse SIR as a nonconvex optimization problem and directly tackle the sparsity constraint by establishing the optimal conditions and iteratively solving them by means of the splicing technique.Without employing convex relaxation on the sparsity constraint and the orthogonal constraint,our algorithm exhibits superior empirical merits,as evidenced by extensive numerical studies.Computationally,our algorithm is much faster than the relaxed approach for the natural sparse SIR estimator.Statistically,our algorithm surpasses existing methods in terms of accuracy for central subspace estimation and best subset selection and sustains high performance even with correlated predictors. 展开更多
关键词 splicing technique best subset selection sliced inverse regression nonconvex optimization sparsity constraint optimal conditions
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Slice-GCN:基于程序切片与图神经网络的智能合约漏洞检测方法
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作者 张人娄 吴胜 +1 位作者 张浩 刘方宇 《信息安全学报》 2025年第1期105-118,共14页
智能合约是一段由计算机代码构成的程序。随着智能合约数量的暴涨,如何利用漏洞检测方法来提升智能合约的安全性显得更加重要。已有的符号执行、模糊测试与形式化验证等漏洞检测方法自动化程度低,而基于序列模型的深度学习方法由于对智... 智能合约是一段由计算机代码构成的程序。随着智能合约数量的暴涨,如何利用漏洞检测方法来提升智能合约的安全性显得更加重要。已有的符号执行、模糊测试与形式化验证等漏洞检测方法自动化程度低,而基于序列模型的深度学习方法由于对智能合约源代码的特征挖掘不足导致检测结果的精度偏低。因此,本文提出一个基于程序切片与图神经网络的以太坊智能合约(简称智能合约)漏洞检测方法Slice-GCN。该方法先对程序进行代码预处理简化程序,再使用基于图可达性和数据流方程的程序切片方法对预处理后的程序进行切片,并将切片结果输入长短期记忆网络(LSTM)中提取智能合约的程序语义特征。接着,简化程序依赖图后将其输入图卷积神经网络中,并提取智能合约的程序结构特征。然后,将智能合约的程序语义特征和结构特征拼接后输入多层感知机(MLP)中,并对智能合约进行漏洞检测。在提出Slice-GCN方法的基础上,针对重入攻击、时间戳依赖及整数溢出三类漏洞,本文对Slice-GCN方法与Oyente、Osiris和Soliditycheck三款智能漏洞检测工具进行了对比实验,并且通过消融实验分析了程序切片、图神经网络及图收缩比例对实验结果的影响。实验结果表明本文提出的方法在各类指标上均有较大提升,能有效提升检测准确度和精度,降低误报率,同时在检测速度上也明显优于传统的智能合约漏洞检测工具。 展开更多
关键词 智能合约 漏洞检测 图神经网络 程序切片
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Slice-Based 6G Network with Enhanced Manta Ray Deep Reinforcement Learning-Driven Proactive and Robust Resource Management
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作者 Venkata Satya Suresh kumar Kondeti Raghavendra Kulkarni +1 位作者 Binu Sudhakaran Pillai Surendran Rajendran 《Computers, Materials & Continua》 2025年第9期4973-4995,共23页
Next-generation 6G networks seek to provide ultra-reliable and low-latency communications,necessitating network designs that are intelligent and adaptable.Network slicing has developed as an effective option for resou... Next-generation 6G networks seek to provide ultra-reliable and low-latency communications,necessitating network designs that are intelligent and adaptable.Network slicing has developed as an effective option for resource separation and service-level differentiation inside virtualized infrastructures.Nonetheless,sustaining elevated Quality of Service(QoS)in dynamic,resource-limited systems poses significant hurdles.This study introduces an innovative packet-based proactive end-to-end(ETE)resource management system that facilitates network slicing with improved resilience and proactivity.To get around the drawbacks of conventional reactive systems,we develop a cost-efficient slice provisioning architecture that takes into account limits on radio,processing,and transmission resources.The optimization issue is non-convex,NP-hard,and requires online resolution in a dynamic setting.We offer a hybrid solution that integrates an advanced Deep Reinforcement Learning(DRL)methodology with an Improved Manta-Ray Foraging Optimization(ImpMRFO)algorithm.The ImpMRFO utilizes Chebyshev chaotic mapping for the formation of a varied starting population and incorporates Lévy flight-based stochastic movement to avert premature convergence,hence facilitating improved exploration-exploitation trade-offs.The DRL model perpetually acquires optimum provisioning strategies via agent-environment interactions,whereas the ImpMRFO enhances policy performance for effective slice provisioning.The solution,developed in Python,is evaluated across several 6G slicing scenarios that include varied QoS profiles and traffic requirements.The DRL model perpetually acquires optimum provisioning methods via agent-environment interactions,while the ImpMRFO enhances policy performance for effective slice provisioning.The solution,developed in Python,is evaluated across several 6G slicing scenarios that include varied QoS profiles and traffic requirements.Experimental findings reveal that the proactive ETE system outperforms DRL models and non-resilient provisioning techniques.Our technique increases PSSRr,decreases average latency,and optimizes resource use.These results demonstrate that the hybrid architecture for robust,real-time,and scalable slice management in future 6G networks is feasible. 展开更多
关键词 sliced network manta ray foraging optimization Chebyshev chaotic map levy flight
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Unknown DDoS Attack Detection with Sliced Iterative Normalizing Flows Technique
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作者 Chin-Shiuh Shieh Thanh-Lam Nguyen +1 位作者 Thanh-Tuan Nguyen Mong-Fong Horng 《Computers, Materials & Continua》 2025年第3期4881-4912,共32页
DDoS attacks represent one of the most pervasive and evolving threats in cybersecurity,capable of crippling critical infrastructures and disrupting services globally.As networks continue to expand and threats become m... DDoS attacks represent one of the most pervasive and evolving threats in cybersecurity,capable of crippling critical infrastructures and disrupting services globally.As networks continue to expand and threats become more sophisticated,there is an urgent need for Intrusion Detection Systems(IDS)capable of handling these challenges effectively.Traditional IDS models frequently have difficulties in detecting new or changing attack patterns since they heavily depend on existing characteristics.This paper presents a novel approach for detecting unknown Distributed Denial of Service(DDoS)attacks by integrating Sliced Iterative Normalizing Flows(SINF)into IDS.SINF utilizes the Sliced Wasserstein distance to repeatedly modify probability distributions,enabling better management of high-dimensional data when there are only a few samples available.The unique architecture of SINF ensures efficient density estimation and robust sample generation,enabling IDS to adapt dynamically to emerging threats without relying heavily on predefined signatures or extensive retraining.By incorporating Open-Set Recognition(OSR)techniques,this method improves the system’s ability to detect both known and unknown attacks while maintaining high detection performance.The experimental evaluation on CICIDS2017 and CICDDoS2019 datasets demonstrates that the proposed system achieves an accuracy of 99.85%for known attacks and an F1 score of 99.99%after incremental learning for unknown attacks.The results clearly demonstrate the system’s strong generalization capability across unseen attacks while maintaining the computational efficiency required for real-world deployment. 展开更多
关键词 Distributed denial of service sliced iterative normalizing flows open-set recognition CYBERSECURITY deep learning
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硬模板构建纳米β-磷酸三钙和纳米羟基磷灰石根管封闭材料
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作者 李倩 曲曼姑丽·阿布都克力木 +1 位作者 邵子瑜 胡杨 《中国组织工程研究》 北大核心 2026年第14期3597-3608,共12页
背景:现阶段根管封闭剂多存在生物相容性、机械力学性能和降解性不佳的缺点,纳米β-磷酸三钙和纳米羟基磷灰石具有较好的生物相容性能、降解性和封闭性,在根管封闭剂领域有重要研究价值。目的:以牙本质片硬模板调控纳米β-磷酸三钙和纳... 背景:现阶段根管封闭剂多存在生物相容性、机械力学性能和降解性不佳的缺点,纳米β-磷酸三钙和纳米羟基磷灰石具有较好的生物相容性能、降解性和封闭性,在根管封闭剂领域有重要研究价值。目的:以牙本质片硬模板调控纳米β-磷酸三钙和纳米羟基磷灰石材料晶体的成核、生长及重构,构建微观形态和三维结构与牙体硬组织结构类似的新型根管封闭材料。方法:收集因智齿阻生而拔除的废弃第三磨牙30颗,制备牙本质片。将不同质量的纳米β-磷酸三钙(或纳米羟基磷灰石)分别溶于蒸馏水中,将溶液倒入含有牙本质片的培养皿中,置于37℃恒温培养箱中12 h,得到10%,20%,30%纳米β-磷酸三钙/牙本质片和10%,20%,30%纳米羟基磷灰石/牙本质片,以单纯的纳米β-磷酸三钙、纳米羟基磷灰石为对照。通过扫描电子显微镜、拉曼光谱、X射线衍射仪和X射线光电子能谱技术对8组样本进行表征和分析。结果与结论:①扫描电子显微镜:在牙本质片的调控下,纳米β-磷酸三钙和纳米羟基磷灰石的微观结构和形貌特征均发生了改变,纳米β-磷酸三钙颗粒形态由不规则多边形变为短棒状、球状,排列成三维团簇状,纳米羟基磷灰石颗粒形态由棒状、针状变为短棒状等多种形态;纳米β-磷酸三钙和纳米羟基磷灰石颗粒有序地排列在牙本质胶原纤维网络之间,并且随着纳米β-磷酸三钙或纳米羟基磷灰石浓度的增加,附着及团聚现象越来越明显,排列越来越紧密。②拉曼光谱:在牙本质片的调控作用下,纳米β-磷酸三钙和纳米羟基磷灰石的官能团未发生改变,但是随着纳米β-磷酸三钙或纳米羟基磷灰石浓度的增加,官能团特征峰的强度增强。③X射线衍射:在牙本质片的调控作用下,纳米β-磷酸三钙和纳米羟基磷灰石的结晶度提升,晶体结构更完整,晶粒变小,其中30%纳米β-磷酸三钙/牙本质片和30%纳米羟基磷灰石/牙本质片的结晶性最好。④X射线光电子能谱:在牙本质片的调控作用下,纳米β-磷酸三钙和纳米羟基磷灰石的元素组成未变,但出现部分化学态变化以及特征峰强度增强特征。⑤结果表明,以牙本质片为硬模板构建的纳米β-磷酸三钙或纳米羟基磷灰石复合材料表征性能稳定,牙本质片对纳米β-磷酸三钙和纳米羟基磷灰石具有一定的调控功能,其中30%纳米β-磷酸三钙/牙本质片、30%纳米羟基磷灰石/牙本质片表征性能更为优异。 展开更多
关键词 纳米β-磷酸三钙 纳米羟基磷灰石 硬模板 牙本质片 表征性能 晶体 微观形貌 分子结构
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基于Slice的H.264并行视频编码算法 被引量:11
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作者 宁华 梅铮 李锦涛 《计算机工程》 EI CAS CSCD 北大核心 2005年第4期181-182,211,共3页
从H.264视频编码标准的特点出发,提出了基于Slice级别的H.264视频编码并行算法,该算法不仅能够保证节点间的负载平衡,减少各节点间数据的依赖关系,还充分利用了已有的计算能力。最后给出了在曙光3000上的实验结果。
关键词 H.264 视频编码 并行 slice
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Effect of slice scope on data slice-based class cohesion metrics 被引量:3
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作者 周毓明 徐宝文 《Journal of Southeast University(English Edition)》 EI CAS 2008年第2期174-177,共4页
This paper suggests that a single class rather than methods should be used as the slice scope to compute class cohesion. First, for a given attribute, the statements in all methods that last define the attribute are c... This paper suggests that a single class rather than methods should be used as the slice scope to compute class cohesion. First, for a given attribute, the statements in all methods that last define the attribute are computed. Then, the forward and backward data slices for this attribute are generated by using the class as the slice scope and are combined to compute the corresponding class data slice. Finally, the class cohesion is computed based on all class data slices for the attributes. Compared to traditional cohesion metrics that use methods as the slice scope, the proposed metrics that use a single class as slice scope take into account the possible interactions between the methods. The experimental results show that class cohesion can be more accurately measured when using the class as the slice scope. 展开更多
关键词 COHESION class data slice metrics OBJECT-ORIENTED
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AVS编码器Slice并行处理算法研究与实现 被引量:2
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作者 许昌满 李国平 王国中 《中国图象图形学报》 CSCD 北大核心 2009年第6期1108-1113,共6页
介绍了一种基于多slice的并行AVS实时编码器的算法研究与实现,基于slice的并行编码的优点是处理速度快、延迟小和数据处理简单,缺点是条纹效应。介绍了一种对基于slice的并行编码带来的条纹效应缺点进行改进的方法。实验结果表明,实现标... 介绍了一种基于多slice的并行AVS实时编码器的算法研究与实现,基于slice的并行编码的优点是处理速度快、延迟小和数据处理简单,缺点是条纹效应。介绍了一种对基于slice的并行编码带来的条纹效应缺点进行改进的方法。实验结果表明,实现标清AVS实时编码器是可行的。 展开更多
关键词 AVS实时编码器 条纹效应 并行处理 条带
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3D-slicer软件辅助神经内镜手术治疗高血压脑出血的临床观察 被引量:3
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作者 蓝欢 马兴才 +4 位作者 赵冠焱 谢昌纪 李光 韦成聪 周志宇 《右江医学》 2020年第10期759-763,共5页
目的观察3D-slicer软件定位在高血压脑出血神经内镜手术中的辅助价值。方法回顾性分析2017年1月至2019年6月神经外科收治的80例高血压脑出血手术患者,根据手术定位方式分组,40例采用3D-slicer软件辅助定位的高血压脑出血神经内镜手术患... 目的观察3D-slicer软件定位在高血压脑出血神经内镜手术中的辅助价值。方法回顾性分析2017年1月至2019年6月神经外科收治的80例高血压脑出血手术患者,根据手术定位方式分组,40例采用3D-slicer软件辅助定位的高血压脑出血神经内镜手术患者作为A组,40例采用常规弦距体表定位的高血压脑出血神经内镜手术患者作为B组,对比观察两组患者的手术时间、术中出血量、平均血肿清除率、住院天数,术前、术后1周GCS评分,术后6个月随访术后神经功能评分(GOS)分级。结果 A组患者的手术时间短于B组,血肿清除率高于B组,术中出血量少于B组,住院时间短于B组(P<0.001)。两组患者的术后1周GCS评分较术前均显著升高(P<0.01),但A组术后1周GCS评分高于B组(P<0.01)。术后6个月GOS分级,A组患者优于B组(P<0.01)。结论使用3D-slice软件辅助神经内镜高血压脑出血手术定位,是一种简单安全、行之有效的治疗方法,可提高患者的临床预后,值得在基层医院推广应用。 展开更多
关键词 高血压脑出血 3D-slicer软件 神经内镜
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A Slice Analysis-Based Bayesian Inference Dynamic Power Model for CMOS Combinational Circuits
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作者 陈杰 佟冬 +2 位作者 李险峰 谢劲松 程旭 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2008年第3期502-509,共8页
To improve the accuracy and speed in cycle-accurate power estimation, this paper uses multiple dimensional coefficients to build a Bayesian inference dynamic power model. By analyzing the power distribution and intern... To improve the accuracy and speed in cycle-accurate power estimation, this paper uses multiple dimensional coefficients to build a Bayesian inference dynamic power model. By analyzing the power distribution and internal node state, we find the deficiency of only using port information. Then, we define the gate level number computing method and the concept of slice, and propose using slice analysis to distill switching density as coefficients in a special circuit stage and participate in Bayesian inference with port information. Experiments show that this method can reduce the power-per-cycle estimation error by 21.9% and the root mean square error by 25.0% compared with the original model, and maintain a 700 + speedup compared with the existing gate-level power analysis technique. 展开更多
关键词 slice analysis Bayesian inference power model CMOS combinational circuit
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一种融合双曲表示与欧几里得表示的源代码漏洞检测方法
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作者 陈旭 陈子雄 +2 位作者 景永俊 王叔洋 宋吉飞 《郑州大学学报(理学版)》 北大核心 2026年第1期19-26,共8页
随着软件系统的日益复杂,源代码漏洞检测成为维护软件安全的关键任务。虽然现在已有各种基于深度学习的漏洞检测方法,但这些方法主要依赖单一的欧氏空间视角提取代码表示结构中的语义特征与结构特征,这不利于检测隐藏在代码深处的漏洞... 随着软件系统的日益复杂,源代码漏洞检测成为维护软件安全的关键任务。虽然现在已有各种基于深度学习的漏洞检测方法,但这些方法主要依赖单一的欧氏空间视角提取代码表示结构中的语义特征与结构特征,这不利于检测隐藏在代码深处的漏洞。为了解决这一问题,提出一种融合双曲表示与欧几里得表示的源代码漏洞检测方法(source code vulnerability detection method fusing hyperbolic representation and Euclidean representation,VulDEHGCN),在两种不同的空间对源代码进行嵌入处理,以不同视角挖掘源代码的漏洞特征,实现更准确的漏洞检测。实验结果表明,与现有的漏洞检测方法相比,VulDEHGCN在准确率、精确率、召回率和F 1得分等关键性能指标上均实现了显著提升,其中,准确率和F 1分数分别达到98.93%和96.63%。消融实验还证实了融合不同视角的代码嵌入的检测性能更优。 展开更多
关键词 漏洞检测 切片级别 双曲空间 欧氏空间 融合表示
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油显示岩心样品Slice实验研究及其启示 被引量:3
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作者 罗情勇 钟宁宁 李可文 《石油实验地质》 CAS CSCD 北大核心 2015年第2期252-258,共7页
钻井、采样、储存和实验过程中对岩石样品所产生的污染,会影响生物标志物信息的真实性,尤其对于前寒武纪的样品而言,甚至有可能会导致地球早期生命起源和演化的错误解释。通过对中元古界洪水庄组含油显示样品的"剥洋葱式"切片... 钻井、采样、储存和实验过程中对岩石样品所产生的污染,会影响生物标志物信息的真实性,尤其对于前寒武纪的样品而言,甚至有可能会导致地球早期生命起源和演化的错误解释。通过对中元古界洪水庄组含油显示样品的"剥洋葱式"切片(Slice)实验,分析了污染对分子生物标志物的影响。结果表明:饱和烃生物标志物在不同"洋葱片"样品之间差异较大,而芳烃生物标志物的差异较小;除个别参数外,大部分生物标志物参数在内外切片样品之间均存在较大差异。由于在内切片中没有检测到甾烷,因此,中元古界洪水庄组中甾烷的存在与否有待进一步验证。切除样品外皮后进行有机地球化学实验分析能更好的避免污染。 展开更多
关键词 污染 切片实验 油显示样品 生物标志物 洪水庄组 华北北部
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Influence of Different Drying Temperatures on Quality of Balsam Pear Slices
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作者 谷俊华 黄斐 《Agricultural Science & Technology》 CAS 2017年第8期1513-1516,1535,共5页
[Objective] The aim was to investigate the effects of different drying temperatures on the physiochemical properties and antioxidant activity of balsam pear slices. [Method] Balsam pear slices were dried at different ... [Objective] The aim was to investigate the effects of different drying temperatures on the physiochemical properties and antioxidant activity of balsam pear slices. [Method] Balsam pear slices were dried at different hot air temperatures, 40, 50, 60, 70 and 80 ℃. [Result] The polyphenols content was highest (2.83 mg/g) in the balsam pear slices dried at 50 ℃, and the flavonoids content was highest (2.584 mg/g) in those dried at 60 ℃. Different drying temperatures had a great impact on the antioxidant capacity of polyphenols in balsam pear. The balsam pear slices dried at 50 ℃ showed the strongest capacity for scavenging DPPH free radicals with IC50 of 0.015 mg/ml, and those dried at 80 ℃ showed the strongest capacity for removing ABTS free radicals with IC50 of 0.0689 mg/ml. [Conclusion] The hot air temperature of 50 ℃ had the least impact on the quality of balsam pear slices. 展开更多
关键词 Balsam pear slice Hot air drying Physiochemical properties Antioxidant activity
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实交错代数上slice正则函数的逼近定理
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作者 陈英伟 陈灿虎 张宝兴 《河北师范大学学报(自然科学版)》 CAS 2022年第1期1-10,共10页
研究了实交错代数上slice正则函数的Runge定理和Carelman型逼近定理.作为特例,在四元数和八元数情形下得出相应的结论.
关键词 slice正则函数 Runge定理 Carleman定理 实交错代数
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Ada软件SLICE分析器(ASA)
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作者 钱红兵 《计算机应用研究》 CSCD 1996年第3期22-24,共3页
对程序进行分析和测试是提高软件可靠性的有效途径。本文介绍的Ada软件SLICE分析器是一种对被测软件进行静态数据流分析的工具,它能缩小用户分析与检查被测程序的范围,帮助用户及时找到所关心的程序段和语句,为保证Ada软件系统的质量、... 对程序进行分析和测试是提高软件可靠性的有效途径。本文介绍的Ada软件SLICE分析器是一种对被测软件进行静态数据流分析的工具,它能缩小用户分析与检查被测程序的范围,帮助用户及时找到所关心的程序段和语句,为保证Ada软件系统的质量、提高开发与维护大型复杂软件系统的效率提供支持。 展开更多
关键词 slice分析 软件可靠性
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多切片模型MSlice格式研究
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作者 王福德 阳佳 《计算机辅助设计与图形学学报》 EI CSCD 北大核心 2003年第8期1044-1048,共5页
在分析了现有其他接口格式如IGES ,STEP和CLI等的利弊之后 ,提出一种新颖的面向多切片模型的数据格式MSlice文件 ,用自行开发的AutoCAD 2 0 0 0下直接切片动态库验证了这一模型 。
关键词 多切片模型 Mslice格式 快速原型制造系统 CAD 计算机辅助设计
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多层螺旋CT冠状动脉成像联合心脏磁共振在急性心肌梗死经皮冠状动脉介入治疗效果评估中的应用价值
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作者 邓成苗 程清涛 +1 位作者 张忠俊 陈琳 《影像科学与光化学》 2026年第1期126-131,共6页
目的:探究多层螺旋CT冠状动脉成像(CTCA)联合心脏磁共振(CMR)在急性心肌梗死(AMI)经皮冠状动脉介入治疗(PCI)效果中的应用价值。方法:选取2022年3月至2023年3月来我院接受PCI治疗的118例AMI患者进行CTCA和CMR检查,术后随访6个月。结果:C... 目的:探究多层螺旋CT冠状动脉成像(CTCA)联合心脏磁共振(CMR)在急性心肌梗死(AMI)经皮冠状动脉介入治疗(PCI)效果中的应用价值。方法:选取2022年3月至2023年3月来我院接受PCI治疗的118例AMI患者进行CTCA和CMR检查,术后随访6个月。结果:CTCA和CMR单独诊断及联合诊断与金标准的一致性较高(Kappa值分别为0.585、0.645、0.793,P<0.001);二者联合诊断AMI患者经PCI治疗发生再狭窄的特异度和准确率明显升高(P<0.05);CTCA、CMR对AMI患者经PCI治疗发生再狭窄的曲线下面积(AUC)分别为0.833、0.870,二者联合诊断的AUC为0.973。结论:CTCA联合CMR对AMI患者经PCI治疗后预后评估具有更高的应用价值,可应用于临床预后评估中,以便准确制定治疗方案。 展开更多
关键词 急性心肌梗死 多层螺旋CT冠状动脉成像 心脏磁共振 经皮冠状动脉介入治疗
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Time Delay Estimation of Target Echo Signal Based on Multi-bright Spot Echoes
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作者 Ge Yu Fan Du +1 位作者 Xiukun Li Yan Li 《哈尔滨工程大学学报(英文版)》 2026年第1期312-325,共14页
Accurate time delay estimation of target echo signals is a critical component of underwater target localization.In active sonar systems,echo signal processing is vulnerable to the effects of reverberation and noise in... Accurate time delay estimation of target echo signals is a critical component of underwater target localization.In active sonar systems,echo signal processing is vulnerable to the effects of reverberation and noise in the maritime environment.This paper proposes a novel method for estimating target time delay using multi-bright spot echoes,assuming the target’s size and depth are known.Aiming to effectively enhance the extraction of geometric features from the target echoes and mitigate the impact of reverberation and noise,the proposed approach employs the fractional order Fourier transform-frequency sliced wavelet transform to extract multi-bright spot echoes.Using the highlighting model theory and the target size information,an observation matrix is constructed to represent multi-angle incident signals and obtain the theoretical scattered echo signals from different angles.Aiming to accurately estimate the target’s time delay,waveform similarity coefficients and mean square error values between the theoretical return signals and received signals are computed across various incident angles and time delays.Simulation results show that,compared to the conventional matched filter,the proposed algorithm reduces the relative error by 65.9%-91.5%at a signal-to noise ratio of-25 dB,and by 66.7%-88.9%at a signal-to-reverberation ratio of−10 dB.This algorithm provides a new approach for the precise localization of submerged targets in shallow water environments. 展开更多
关键词 Multi-bright spot echoes Time-delay estimation Target echo signal Frequency sliced wavelet transform Fractional order fourier transform
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Lipopolysaccharide preconditioning induces protection against lipopolysac-charide -induced neurotoxicity in organotypic midbrain slice culture 被引量:3
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作者 丁晔 李良 《Neuroscience Bulletin》 SCIE CAS CSCD 2008年第4期209-218,共10页
Objective To identify the protective effect of lipopolysaccharide (LPS) preconditioning against LPS-induced inflammatory damage in dopaminergic neurons of midbrain slice culture and the possible mechanisms. Methods ... Objective To identify the protective effect of lipopolysaccharide (LPS) preconditioning against LPS-induced inflammatory damage in dopaminergic neurons of midbrain slice culture and the possible mechanisms. Methods After cultured in vitro for 14 d, the rat organotypic midbrain slices were pretreated with different concentrations (0, 1, 3, 6 or 10 ng/mL) of LPS for 24 h followed by treatment with 100 ng/mL LPS for 72 h. The whole slice viability was detelmined by measurement of the activity of lactic acid dehydrogenase (LDH). Tyrosine hydroxylase-immunoreactive (TH-IR) neurons and CD 1 1 b/c equivalent-immunoreactive (OX-42-IR) microglia in the slices were observed by immunohistochemical method, and tumor necrosis factor-α (TNF-α levels in the culture media were detected by enzymelinked immunosorbent assays (ELISA). Results In the slices treated with 100 ng/mL LPS for 72 h, the number of TH-IR neurons reduced from 191± 12 in the control slices to 46±4, and the LDH activity elevated obviously (P 〈 0.01), along with remarkably increased number of OX-42-IR cells and production of TNF-α (P 〈 0.01). Preconditioning with 3 or 6 ng/mL LPS attenuated neuron loss (the number of TH-IR neurons increased to 126± 12 and 180± 13, respectively) and markedly reduced LDH levels (P 〈 0.05), accompanied by significant decreases of OX-42-IR microglia activation and TNF-α production (P 〈 0.05). Conclusion Low-dose LPS preconditioning could protect dopaminergic neurons against inflammatory damage in rat midbrain slice culture, and inhibition of microglial activation and reduction of the proinflammatory factor TNF-α production may contribute to this protective effect. Further understanding the underlying mechanism of LPS preconditioning may open a new window for treatment of Parkinson's disease. 展开更多
关键词 LIPOPOLYSACCHARIDE PRECONDITIONING neuroprotection organotypic midbrain slice culture dopaminergic neuronsinflammation MICROGLIA tumor necrosis factor-α
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数字病理切片在基层病理实习教学中的应用探索
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作者 杨长绍 陆继辉 +1 位作者 许凌瑞 苏新鹏 《临床医学研究与实践》 2026年第2期170-173,共4页
目的探讨数字病理切片在基层病理实习教学中的应用效果。方法选取禄丰市人民医院2024年6月至2025年3月的56名实习学生作为研究对象,其中医学检验专业25名,临床医学专业31名,随机将其分为试验组和对照组,每组28人。试验组采用数字病理切... 目的探讨数字病理切片在基层病理实习教学中的应用效果。方法选取禄丰市人民医院2024年6月至2025年3月的56名实习学生作为研究对象,其中医学检验专业25名,临床医学专业31名,随机将其分为试验组和对照组,每组28人。试验组采用数字病理切片进行教学,对照组采用传统的显微镜和玻璃切片教学。通过考核成绩、病变的特征辨认及教学效果满意度问卷调查评估两组学生的学习效果。结果两组学生的出科成绩均较入科成绩显著提高(P<0.05);试验组的出科成绩明显高于对照组,差异具有统计学意义(P=0.037)。试验组学生不需要教师示教就能找到病变特征的人数占比(57.14%)显著高于对照组(25.00%),差异具有统计学意义(P=0.013);教学满意度评价中,试验组教学方法在促进实习教学内容理解、快速定位典型组织结构、激发学生学习兴趣、提升自主学习能力及加强师生互动方面具有显著优势(P<0.05)。结论在基层病理实习教学中,数字病理切片教学不仅有效提升了教学效率和教学质量,还增强了学生的自主学习能力,激发了学习热情和探究兴趣,同时促进了师生间的教学互动。 展开更多
关键词 数字病理切片 基层病理 实习 教学质量
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