Compression

压缩
  • 文章类型: Journal Article
    点云是利用包括3D位置和属性的无序点的对象或场景的表示。点云模仿自然形态的能力已获得不同应用领域的极大关注,例如虚拟现实和增强现实。然而,点云,尤其是那些代表动态场景或运动物体的人,由于其巨大的数据量,必须有效地压缩。用于动态点云的最新基于视频的点云压缩(V-PCC)标准使用计算昂贵的正态估计将3D点云划分为许多补丁,分割,和细化。面片被投影到2D平面上以应用现有的视频编码技术。该过程通常导致丢失接近度信息和一些原始点。这种损失引起对用户感知产生不利影响的伪像。该方法在块生成前基于形状相似性和遮挡分割动态点云。这种分割策略通过利用点的密度和遮挡来帮助保持点的接近度并保留更多的原始点。实验结果证明,对于几个基准视频序列的几何和纹理数据,该方法在率失真性能和主观质量测试方面明显优于V-PCC标准和其他相关方法。
    A point cloud is a representation of objects or scenes utilising unordered points comprising 3D positions and attributes. The ability of point clouds to mimic natural forms has gained significant attention from diverse applied fields, such as virtual reality and augmented reality. However, the point cloud, especially those representing dynamic scenes or objects in motion, must be compressed efficiently due to its huge data volume. The latest video-based point cloud compression (V-PCC) standard for dynamic point clouds divides the 3D point cloud into many patches using computationally expensive normal estimation, segmentation, and refinement. The patches are projected onto a 2D plane to apply existing video coding techniques. This process often results in losing proximity information and some original points. This loss induces artefacts that adversely affect user perception. The proposed method segments dynamic point clouds based on shape similarity and occlusion before patch generation. This segmentation strategy helps maintain the points\' proximity and retain more original points by exploiting the density and occlusion of the points. The experimental results establish that the proposed method significantly outperforms the V-PCC standard and other relevant methods regarding rate-distortion performance and subjective quality testing for both geometric and texture data of several benchmark video sequences.
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  • 文章类型: Journal Article
    随着更高的时空分辨率触觉传感系统正在开发用于假肢,可穿戴设备,和其他生物医学应用,它们需要更快的采样率并生成更大的数据流。稀疏的转换可以通过压缩实现压缩采样和高效的数据存储来缓解这些要求。然而,关于触觉交互的最佳稀疏化转换的研究还很滞后。在这项工作中,我们构建了一个正交和双正交小波变换库,作为触觉交互的稀疏变换,并比较了它们在压缩和稀疏性方面的权衡。我们在公开可用的高密度触觉对象抓取数据集(548传感器触觉手套,抓住26个对象)。此外,我们研究了小波变换-1D,2D,或3D-最好压缩这些触觉交互。我们的结果表明,小波变换在压缩触觉数据方面非常有效,并且可以导致非常稀疏和紧凑的触觉表示。此外,我们的结果表明,一维变换实现了最稀疏的表示,其次是3D,最后是2D。总的来说,用于粗略逼近的最佳小波是在时间上评估的Symlet4,它可以稀疏到0.5%的稀疏性,并将10位触觉数据压缩到平均每像素0.04位。未来的研究可以利用本文的结果来帮助大型触觉阵列的压缩采样,并释放计算资源,以便在计算受限的移动平台(如神经假体)上进行实时处理。
    As higher spatiotemporal resolution tactile sensing systems are being developed for prosthetics, wearables, and other biomedical applications, they demand faster sampling rates and generate larger data streams. Sparsifying transformations can alleviate these requirements by enabling compressive sampling and efficient data storage through compression. However, research on the best sparsifying transforms for tactile interactions is lagging. In this work we construct a library of orthogonal and biorthogonal wavelet transforms as sparsifying transforms for tactile interactions and compare their tradeoffs in compression and sparsity. We tested the sparsifying transforms on a publicly available high-density tactile object grasping dataset (548 sensor tactile glove, grasping 26 objects). In addition, we investigated which dimension wavelet transform-1D, 2D, or 3D-would best compress these tactile interactions. Our results show that wavelet transforms are highly efficient at compressing tactile data and can lead to very sparse and compact tactile representations. Additionally, our results show that 1D transforms achieve the sparsest representations, followed by 3D, and lastly 2D. Overall, the best wavelet for coarse approximation is Symlets 4 evaluated temporally which can sparsify to 0.5% sparsity and compress 10-bit tactile data to an average of 0.04 bits per pixel. Future studies can leverage the results of this paper to assist in the compressive sampling of large tactile arrays and free up computational resources for real-time processing on computationally constrained mobile platforms like neuroprosthetics.
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  • 文章类型: Journal Article
    基于机电致动器的压缩系统需要对其动力学有很好的理解以获得更好的性能。本文研究了具有两个旋转臂的机电系统的非线性动力学,该系统受到正弦激励以进行流体压缩。提出了将两个气球交替压缩的物理模型,并建立了对其动力学进行转换的数学方程。我们强调一些控制参数的影响,即电源电压,不连续位置和粘弹性比对臂角位移行为的影响。该研究还通过忽略系统电气部分中的电感来完成。可以得出,尽管手臂在规则运动期间表现出周期性运动,气球的压缩会导致向多周期或混沌动力学的转变,偶尔恢复到周期性。实验结果与数值模拟结果吻合良好,R系统比RL系统更接近实验结果。这些发现对利用泵技术的各种环境应用具有重要意义。
    Compression systems based electromechanical actuators require a good understanding of their dynamics for a better performance. This paper deals with the study of the nonlinear dynamics of an electromechanical system with two rotating arms subjected to a sinusoidal excitation for fluid compression purposes. The physical model integrating two balloons to be compressed by the arms alternately is presented and the mathematical equations traducing their dynamics are established. We emphasize on the influence of some control parameters namely the supply voltage, the discontinuity position and the viscoelastic ratio on the behaviour of the angular displacement of the arms. The study is also done by neglecting the inductance in the electrical part of the system. It is obtained that while the arms exhibit periodic motion during regular movement, compression of the balloons induces a shift to multi-periodic or chaotic dynamics, occasionally reverting to periodicity. Experimental and numerical simulation results demonstrate good agreement, with the R-system approximating more experimental outcomes than the RL-system. These findings hold significant implications for various environmental applications utilizing pump technology.
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  • 文章类型: Case Reports
    残余的血管移植物可能由于邻近神经结构的压缩而导致显著的神经功能缺损。我们在体外膜氧合拔管和上肢动静脉瘘去除后的两种情况下报告了这一发现。在这两种情况下,去除移植物,补片动脉切开术,和外部神经溶解导致神经功能显着恢复。我们回顾术前检查,诊断研究,和治疗的技术方法,以提高血管和心血管外科医生的认可度,并通过多学科方法证明安全有效的管理选择。
    Remnant vascular grafts may result in significant neurological deficits owing to compression of adjacent neural structures. We report this finding in two cases after extracorporeal membrane oxygenation decannulation and removal of an arteriovenous fistula in the upper extremity. In both cases, removal of the graft, patch arteriotomy, and external neurolysis resulted in significant recovery of neurological function. We review the preoperative workup, diagnostic studies, and technical approach to treatment in an effort to increase recognition among vascular and cardiovascular surgeons and to demonstrate a safe and effective management option through a multidisciplinary approach.
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  • 文章类型: Journal Article
    以前的研究表明,硫辛酸等药物具有软化晶状体的能力,为治疗老花眼提供了一条有希望的途径。在此类药物的临床前阶段遇到的一个障碍是需要在实验模型中精确测量晶状体弹性。这项研究旨在评估25-羟基胆固醇的影响,硫辛酸,和奥贝胆酸对使用定制的弹性计系统的小鼠镜片的粘弹性特性。在来自两个年龄组的C57BL/6J雌性小鼠的透镜上获得数据:年轻(年龄:8-10周)和年龄(年龄:32-43周)。OD透镜用作对照,并且处理OS透镜。将对照镜片浸入Dulbecco的改良鹰培养基(DMEM)中,并将治疗镜片浸入含有25-羟基胆固醇(5岁和5岁)的复合溶液中,硫辛酸2.35mM(5岁和5岁),硫辛酸在0.66mM(5岁),或奥贝胆酸(5岁)在37ºC持续18小时。治疗后,将小鼠透镜放置在定制的弹性计系统内的DMEM填充室中,该系统记录当透镜以50μm/s的速度压缩600μm时的载荷和透镜形状。在压缩期间和应力松弛期间连续记录载荷。压缩阶段用线性函数拟合以量化镜片刚度。应力松弛阶段与提供松弛时间常数(t1,t2,t3)的3项指数松弛模型拟合,和平衡负荷。镜头刚度,比较了对照组和治疗组的时间常数和平衡负荷.结果显示,对照组的刚度随年龄增加而增加(年轻:1.16±0.11g/mm,年龄:1.29±0.14g/mm),弛豫时间常数随年龄而降低(年轻:t1=221.9±29.0s,t2=24.7±3.8s,t3=3.12±0.87s,旧:t1=183.0±22.0s,t2=20.6±2.6s和t3=2.24±0.43s)。在测试的化合物中,只有25-羟基胆固醇在晶状体硬度方面产生统计学上显著的变化,弛豫时间常数,和平衡负荷。总之,较旧的鼠标镜片比年轻的鼠标镜片更硬,粘性更低。值得注意的是,用硫辛酸治疗后,未观察到晶状体硬度的显着变化,与以前的发现相反。
    Previous studies have shown that pharmaceutical agents such as lipoic acid have the ability to soften the lens, presenting a promising avenue for treating presbyopia. One obstacle encountered in the preclinical stage of such agents is the need for precise measurements of lens elasticity in experimental models. This study aimed to evaluate the effects of 25-hydroxycholesterol, lipoic acid, and obeticholic acid on the viscoelastic properties of mouse lenses using a custom-built elastometer system. Data were acquired on lenses from C57BL/6J female mice from two age groups: young (age: 8-10 weeks) and old (age: 32-43 weeks). OD lenses were used as the control and OS lenses were treated. Control lenses were immersed in Dulbecco\'s Modified Eagle Medium (DMEM) and treatment lenses were immersed in a compound solution containing 25-hydroxycholesterol (5 young and 5 old), lipoic acid at 2.35 mM (5 young and 5 old), lipoic acid at 0.66 mM (5 old), or obeticholic acid (5 old) at 37 °C for 18 h. After treatment, the mouse lenses were placed in a DMEM-filled chamber within a custom-built elastometer system that recorded the load and lens shape as the lens was compressed by 600 μm at a speed of 50 μm/s. The load was continuously recorded during compression and during stress-relaxation. The compression phase was fit with a linear function to quantify lens stiffness. The stress-relaxation phase was fit with a 3-term exponential relaxation model providing relaxation time constants (t1, t2, t3), and equilibrium load. The lens stiffness, time constants and equilibrium load were compared for the control and treated groups. Results revealed an increase in stiffness with age for the control group (young: 1.16 ± 0.11 g/mm, old: 1.29 ± 0.14 g/mm) and relaxation time constants decreased with age (young: t1 = 221.9 ± 29.0 s, t2 = 24.7 ± 3.8 s, t3 = 3.12 ± 0.87 s, old: t1 = 183.0 ± 22.0 s, t2 = 20.6 ± 2.6 s and t3 = 2.24 ± 0.43 s). Among the compounds tested, only 25-hydroxycholesterol produced statistically significant changes in the lens stiffness, relaxation time constants, and equilibrium load. In conclusion, older mouse lenses are stiffer and less viscous than young mouse lenses. Notably, no significant change in lens stiffness was observed following treatment with lipoic acid, contrary to previous findings.
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  • 文章类型: Case Reports
    Guyon管的尺骨神经压迫并不是一个常见的实体,血管病变很少作为该综合征的病原体而涉及。
    方法:我们报告了一例年轻男性患者,因尺动脉动脉瘤导致的Guyon管综合征入院,并接受了手术减压。术后过程顺利,患者对结果感到满意。
    Guyon管综合征涉及许多病因,这些病因可以分组。以前的治疗尝试,症状的持续时间和严重程度以及潜在的病因决定了治疗方案。邻近的血管增大不是Guyon管受压的常见原因,文献中报道了一些病例。在大多数报道中,通过打开和释放Guyon管的顶部并切除动脉瘤的手术治疗有助于取得良好的疗效。
    结论:Guyon管综合征的频率低于肘管综合征或腕管综合征,并且已经描述了许多病原体。血管病变不是压迫腕部尺神经的常见原因,通过这种情况,我们将其视为另一种可能的病因,需要适当的治疗才能获得更好的结果。
    UNASSIGNED: The ulnar\'s nerve compression at the Guyon\'s canal is not a frequent entity add to it that vascular lesions are rarely involved as a causative agent of this syndrome.
    METHODS: We report a case of a young male patient admitted in our department for a Guyon\'s canal syndrome due to an aneurysm of the ulnar artery and underwent a surgical decompression. Post-operative course was uneventful and the patient was satisfied with the result.
    UNASSIGNED: Many etiologies are involved in the Guyon\'s canal syndrome and these etiologies can be arranged into groups. Previous treatment attempts, the duration and severity of the symptoms and the underlying etiology dictate the treatment options. Adjacent vascular enlargement is not a usual cause of Guyon\'s canal compression and a few case reports were reported in the literature. Surgical treatment by opening and releasing the roof of Guyon\'s canal and removing the aneurysm helped to achieve good outcome in most reports.
    CONCLUSIONS: Guyon\'s canal syndrome is less frequent than both cubital tunnel syndrome or carpal tunnel syndrome and many causative agents have been described. Vascular lesions are not the usual cause of compressing the ulnar nerve at the wrist and through this case we spotlighted this entity as another possible etiology requiring an adequate treatment for a better outcome.
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  • 文章类型: Journal Article
    高剪切湿法制粒(HSWG)在片剂生产中的广泛应用主要是因为它在改善流动性方面的优势,粉末处理,进程运行时间,大小分布,防止隔离。在线过程分析技术测量对于捕获详细的粒子动力学和呈现实时数据以揭示HSWG过程的复杂性并最终用于过程控制至关重要。这项研究提供了一个机会,通过测量造粒碗的扭矩和施加在粉末床内新型力探针上的力,来预测颗粒和片剂的特性。发现在线力测量比扭矩测量对造粒过程更敏感。特征力曲线呈现了高剪切湿法制粒的整体指纹,其中颗粒形成的演变可以提高我们对造粒过程的理解。这提供了与颗粒性质有关的丰富信息,确定粘合剂液体的均匀分布,和潜在的造粒终点。使用以表面为中心的表面响应实验设计(DoE),从一系列关键工艺参数的实验高剪切混合器中获得数据。利用进化方程的发现,从DOE矩阵中建立了封闭形式的分析模型。该模型能够仅基于在线数据提供预期片剂拉伸强度的强预测性指示。与其他AI方法(如人工神经网络)相比,使用封闭形式的数学方程具有显着的优势,显著提高了可解释性/可询问性,和最小的推理成本,因此,该模型可用于实时决策和过程控制。准确预测的能力,实时,从上游数据中获得所需片剂拉伸强度所需的压实力具有确保压缩机设置迅速达到并保持在最佳值的潜力,从而最大限度地提高效率和减少浪费。
    High shear wet granulation (HSWG) is widely used in tablet manufacturing mainly because of its advantages in improving flowability, powder handling, process run time, size distribution, and preventing segregation. In line process analytical technology measurements are essential in capturing detailed particle dynamics and presenting real-time data to uncover the complexity of the HSWG process and ultimately for process control. This study presents an opportunity to predict the properties of the granules and tablets through torque measurement of the granulation bowl and the force exerted on a novel force probe within the powder bed. Inline force measurements are found to be more sensitive than torque measurements to the granulation process. The characteristic force profiles present the overall fingerprint of the high shear wet granulation, in which the evolution of the granule formation can improve our understanding of the granulation process. This provides rich information relating to the properties of the granules, identification of the even distribution of the binder liquid, and potential granulation end point. Data were obtained from an experimental high shear mixer across a range of key process parameters using a face-centred surface response design of experiment (DoE). A closed-form analytical model was developed from the DOE matrix using the discovery of evolutionary equations. The model is able to provide a strong predictive indication of the expected tablet tensile strength based only on the data in-line. The use of a closed form mathematical equation carries notable advantages over other AI methodologies such as artificial neural networks, notably improved interpretability/interrogability, and minimal inference costs, thus allowing the model to be used for real-time decision making and process control. The capability of accurately predicting, in real time, the required compaction force required to achieve the desired tablet tensile strength from upstream data carries the potential to ensure compression machine settings rapidly reach and are maintained at optimal values, thus maximising efficiency and minimising waste.
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  • 文章类型: Case Reports
    遗传性神经病伴责任压力性麻痹(HNPP)通常由压迫引起,无痛,复发性遗传性神经病,局灶性运动和感觉受累。它始于青春期和成年期。HNPP中最常见的受影响的神经是尺骨,腓骨,径向,正中神经.在这篇文章中,我们介绍了一名31岁的女性患者,患有先前未描述的HNPP病例,在瑜伽的乌鸦位置后,由于the神经被困在螺旋槽中,因此出现了手腕下垂。
    Hereditary neuropathy with liability pressure palsies (HNPP) is usually caused by compression and is an episodic, painless, recurrent hereditary neuropathy with focal motor and sensory involvement. It begins in adolescence and young adulthood. The most commonly affected nerves in HNPP are the ulnar, peroneal, radial, and median nerves. In this article, we present a 31-year-old female patient with a previously undescribed case of HNPP, which presented with wrist drop due to the trapping of the radial nerve in the spiral groove after the crow position in yoga.
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  • 文章类型: Journal Article
    随着人工智能(AI)系统在放射学中的应用越来越多,对更大带宽和计算资源的需求增加可能导致医疗保健提供商和人工智能供应商的基础设施成本增加。为此,我们开发了岛屿,智能流框架,以解决当前成像基础架构中的低效率问题。我们的框架从视频点播平台中汲取灵感,以最佳分辨率将医疗图像智能地流式传输给AI供应商,以便使用渐进式编码从单个高分辨率副本中进行推断。我们假设ISLE可以大大减少AI推理的带宽和计算需求,同时增加吞吐量(即,AI系统每秒处理的扫描次数)。我们通过流式胸部X射线进行分类和腹部CT扫描以进行肝脏和脾脏分割,并将其与每个数据集的原始版本进行比较来评估我们的框架。对于分类,我们的结果表明,ISLE减少了至少92%和88%的数据传输和解码时间,分别,同时提高吞吐量3.72倍以上。对于这两个分段任务,ISLE将数据传输和解码时间至少减少了82%和88%,分别,同时将吞吐量提高2.9倍以上。在所有三个任务中,ISLE流式数据对AI系统的诊断性能没有影响(均P>0.05).因此,我们的研究结果表明,我们的框架可以通过改善临床环境中AI部署的数据和计算效率来解决当前成像基础设施中的低效率问题,而不会影响使用AI系统的临床决策.
    As the adoption of artificial intelligence (AI) systems in radiology grows, the increase in demand for greater bandwidth and computational resources can lead to greater infrastructural costs for healthcare providers and AI vendors. To that end, we developed ISLE, an intelligent streaming framework to address inefficiencies in current imaging infrastructures. Our framework draws inspiration from video-on-demand platforms to intelligently stream medical images to AI vendors at an optimal resolution for inference from a single high-resolution copy using progressive encoding. We hypothesize that ISLE can dramatically reduce the bandwidth and computational requirements for AI inference, while increasing throughput (i.e., the number of scans processed by the AI system per second). We evaluate our framework by streaming chest X-rays for classification and abdomen CT scans for liver and spleen segmentation and comparing them with the original versions of each dataset. For classification, our results show that ISLE reduced data transmission and decoding time by at least 92% and 88%, respectively, while increasing throughput by more than 3.72 × . For both segmentation tasks, ISLE reduced data transmission and decoding time by at least 82% and 88%, respectively, while increasing throughput by more than 2.9 × . In all three tasks, the ISLE streamed data had no impact on the AI system\'s diagnostic performance (all P > 0.05). Therefore, our results indicate that our framework can address inefficiencies in current imaging infrastructures by improving data and computational efficiency of AI deployments in the clinical environment without impacting clinical decision-making using AI systems.
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  • 文章类型: Journal Article
    纺织材料的机械性能在决定其舒适性方面起着至关重要的作用,功能,性能,安全,和美学。了解和优化这些属性对于满足消费者需求至关重要。机械性能的关键方面,如表面粗糙度,耐磨性,和压缩,对材料的触感和耐用性有重大影响,正如各种研究所证明的那样。本研究重点分析了不同聚合物纱线生产的材料的力学性能及其在组合老化因素下的变化。研究结果强调了纺织品耐磨性和表面粗糙度测量的重要性,特别是对于老化的材料。虽然使用再生聚酯纱线是可持续的,并提供更高的拉伸强度等优点,结果表明,使用传统的聚酯纱线是更有利的整体,因为它具有较高的耐磨性,更光滑的表面纹理,和更好的弹性保持老化后。提出的见解对于设计高性能运动服至关重要,这在当今的竞争环境中至关重要。
    The mechanical properties of textile materials play a crucial role in determining their comfort, functionality, performance, safety, and aesthetics. Understanding and optimizing these properties is essential to meet consumer demands. Key aspects of mechanical properties, such as surface roughness, abrasion resistance, and compression, have a significant impact on the touch and durability of the material, as demonstrated by various research studies. This study focuses on analyzing the mechanical properties of materials produced of different polymer yarns and their changes under combined aging factors. The findings emphasize the significance of textile abrasion resistance and surface roughness measurement, particularly for aged materials. Although the use of recycled polyester yarn is sustainable and offers advantages such as higher tensile strength, the results have shown that the use of conventional polyester yarn is more advantageous overall as it has higher abrasion resistance, a smoother surface texture, and better elasticity retention after aging. The insights presented are vital for designing high-performance sportswear, which is crucial in today\'s competitive environment.
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