Full Compression Research Articles

Orientation effects on the fracture behaviour of additively manufactured stainless steel 316L subjected to high cyclic fatigue

In this paper, stainless steel 316L (SS316L) bars were additively manufactured (AM) in three orientations (Z – vertical, XY – horizontal, ZX45 – midway between vertical and horizontal) by using the Laser Powder Bed Fusion Melting (LPBF-M) method. The AM specimens were subjected to load control fatigue testing under full tension and compression (R = -1) at stress amplitudes ± 350, ±400 and ± 450 MPa. The XY and ZX45 printing orientations were found to significantly improve service life. Although similar strain response was found for each orientation when the same stress amplitude was applied, slightly different fracture mechanisms were identified during the post-mortem surface observations.

Optimal design and operation of the hybrid absorption-compression chiller plants - Energy and economic analysis

A hybrid network integrating absorption and compression chillers is a suitable solution to respond to the variable cooling demand in a large-scale chiller plant, in regions with multiple energy sources. However, the design and control challenges of such networks remain uncharted, lacking a comprehensive approach. This study presents a general procedure for designing a hybrid chiller network for a building with an arbitrary annual cooling demand distribution. The procedure determines the optimal configuration considering the different capacity ratios of absorption to compression chillers, chiller numbers, and arrangements. Utilizing the Particle Swarm Optimization algorithm, the optimal chiller loading distribution is found for each configuration. Life cycle cost analysis aids in selecting the optimal configuration. Simulations conducted in TRNSYS, reveal that optimal energy and economic choices depend on the natural gas and electricity price ratio. The best energy performance occurs at a low capacity ratio, while the economic trend varies with capacity ratio for different price ratios. The potential reduction in life cycle cost associated with the configuration, when compared to the full absorption baseline and the full compression baseline, can reach up to 7,210,000 $ (72.6%) and 724,000 $ (24.5%), respectively. From an environmental perspective, compared to the full absorption baseline and the full compression baseline, hybrid chiller configurations reduce the CO2 emissions for up to 899 tons (68.8%) and 52 tons (11.3%), respectively.

Behavior of glued laminated bamboo in compression perpendicular to the grain at elevated temperature

The study investigated the behavior of glued laminated bamboo (GLB) subjected to compression in different loading configurations. The temperature range of 20 °C to 250 °C and the loading configurations of full surface and local loading perpendicular to the grain direction were considered. The results were discussed in terms of the failure mode, load-deformation curve, and compressive strength, revealing the effect of varying loading configurations and temperatures. In the full surface compression specimens, inclined shear surfaces were observed, while the failure mode of the local compression specimens was characterized by cracks in the adhesive layers. Despite the different failure modes, the load-deformation curves were similar. Due to the confined dilation, the strength under local compression showed higher values than that under full surface compression. As the temperature increases, there is a gradual decrease in both the full surface and local compressive strength. The reduction factors of compressive strength were fitted using a bilinear function. Subsequently, a model, based on van der Put's equation, was proposed for the prediction of full surface and local compressive strength at elevated temperatures. Additionally, the scanning electron microscopy was used to observe the microstructure of thermally treated GLB specimens, and the impact of temperature on morphological changes was discussed.

Metamaterials with Poisson's ratio discontinuity by means of fragmentation–reconstitution rotating units

This paper presents for the first time two types of metamaterials based on the fragmentation–reconstitution of rotating units in order to produce Poisson's ratio discontinuity at the original state. For both metamaterials, each rotating unit takes the form of a rhombus that comprises eight sub-units. During on-axis stretching, each rhombus fragments into eight rotating sub-units. When the prescribed strain is reversed, these eight sub-units reconstitute back into a single rotating rhombus such that they rotate as a rigid body. Using geometrical construction, the incremental Poisson's ratio was established at the original state. In the case of large deformation, the finite Poisson's ratio was formulated in conjunction with the maximum allowable rotations for full stretching along both axes and for full compression. The family of on-axes Poisson's ratio versus rotational angles for various shape descriptors displays a fork-shaped distribution with discontinuity at the original state. Two major distinguishing factors of these metamaterials—property discontinuity at the original state with constant and variable Poisson's ratio under compression and tension, respectively—allow them to function in ways that cannot be fully performed by conventional materials or even by auxetic materials and metamaterials.

Evaluation of healable epoxy matrices as covalent adaptive networks in uniaxial compression

Vitrimers provide dynamic bonding that can allow a degree of self-healing capability in cross-linked resins. A commercial amine-cured epoxy resin, Prime 27, showed a compressive yield stress, measured in compression, of 88 ± 2 MPa and a compression modulus of 3.41 ± 0.03 GPa. This base resin was modified by incorporating various proportions of two commercial vitrimers, either Thioplast EPS35 (an aliphatic epoxy-terminated polysulfide) or Vitrimax T130 (an imine-cured DGEBA epoxy resin). The addition of increasing amounts of Thioplast EPS35 into the resin led to a rapid drop in the glass transition temperature of the matrices and also a reduction in compressive performance. After an initial test in quasi-static, uniaxial compression, samples containing vitrimers were heated for 1 h at 100 °C and then subjected to a second compression test; all of the matrices loaded with Thioplast EPS35 were able to recover their full initial compression performance. Addition of increasing amounts of Vitrimax T130 to the same commercial epoxy resin did not cause any change in its glass transition temperature. However, after initial compression testing, followed by heating (1 h at 100 °C), only the formulation containing 40 wt% Vitrimax T130-loaded matrix regained its full initial compressive performance. Optimal results in terms of healing capability, measured as the recovery of the initial compression performance during a second identical test, following a heating step, were achieved by incorporating 10 wt% of EPS35 or 40 wt% Vitrimax T130, with little to no drop in glass transition temperature. For these selected formulations, the incorporation of 10% Thioplast EPS35 in Prime 27 gave a yield stress of 83 ± 2 MPa and a compression modulus of 3.13 ± 0.02 GPa, while the addition of 40% Vitrimax T130 gave a yield stress of 79 ± 2 MPa and a compression modulus of 3.30 ± 0.02 GPa.

Toward Compact Transformers for End-to-End Object Detection With Decomposed Chain Tensor Structure

DEtection TRansformer (DETR) is a recently proposed method that streamlines the detection pipeline and achieves competitive results against two-stage detectors such as Faster-RCNN. The DETR models get rid of complex anchor generation and post-processing procedures thereby making the detection pipeline more intuitive. However, the numerous redundant parameters in transformers make the computation and storage of the DETR models intensive, which seriously hinder them to be deployed on the resources-constrained devices. In this paper, to obtain a compact end-to-end detection framework, we propose to deeply compress the transformers with low-rank tensor decomposition. The basic idea of our tensor-based compression method is to represent the large-scale weight matrix in one network layer with a chain of low-order matrices. Furthermore, we show that redundant attention heads will hinder the performance of detection transformers. We thus propose a gated multi-head attention (GMHA) module to suppress the redundant attention information by normalizing the attention heads. In GMHA, each attention head has an independent gate to determine the passed attention value, thereby down-weighting the uninformative heads. The accuracy drop of the tensor-compressed DETR models can be mitigated by applying GMHA modules. Lastly, to obtain fully compressed DETR models, a low-bitwidth quantization technique is introduced for further reducing the model storage size. Based on the proposed methods, we can achieve significant parameter and model size reduction while maintaining high detection performance. We conduct extensive experiments on the COCO and PASCAL VOC datasets to validate the effectiveness of our tensor-compressed (tensorized) DETR models. The experimental results on the COCO benchmark show that we can attain <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3.7\times $ </tex-math></inline-formula> full model compression with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$482\times $ </tex-math></inline-formula> feed forward network (FFN) parameter reduction and only 0.6 points accuracy drop.

Comparison of full thread compression cannulated screw and partial thread cannulated screw in treatment of femoral neck fracture

To compare the effectiveness of full thread compression cannulated screw and partial thread cannulated screw in the treatment of femoral neck fracture. A retrospective analysis was made on 152 patients with femoral neck fractures, who met the selection criteria, between April 2013 and February 2021. The fractures were fixed with the full thread compression cannulated screws in 74 cases (trial group) and the partial thread cannulated screws in 78 cases (control group). There was no significant difference in general data such as age, gender, body mass index, cause of injury, time from injury to operation, and the side, Garden typing, Pauwels typing of fracture between the two groups (P>0.05). The operation time, intraoperative blood loss, hospital stay, follow-up time, and Harris score were recorded in both groups. X-ray films were performed to evaluate the quality of fracture reduction and bone healing, the changes of neck-shaft angle, the changes of femoral neck, as well as the occurrence of internal fixation failure, screw back-out, and osteonecrosis of the femoral head. There was no significant difference in operation time and hospital stay between the two groups (P>0.05). However, the intraoperative blood loss in the trial group was significantly lower than that in the control group (P<0.05). Patients in both groups were followed up, with the follow-up time of (24.11±4.04) months in the trial group and (24.10±4.42) months in the control group, and the difference was not significant (P>0.05). Postoperative X-ray films showed that there was no significant difference in fracture reduction grading between the two groups (P>0.05). Six cases in the trial group developed bone nonunion and 7 cases in the control group, the fractures of the other patients healed, and the healing time was significantly shorter in the trial group than in the control group (P<0.05). There was no significant difference in the incidence of bone nonunion between the two groups (P>0.05). During follow-up, 2 cases in the trial group and 5 cases in the control group had osteonecrosis of the femoral head, the difference was not significant (P>0.05), and the patients with osteonecrosis of the femoral head were treated with secondary operation. The screw back-out occurred in 3 cases of the trial group and in 9 cases of the control group, showing no significant difference (P>0.05). But the screw back-out distance was significantly shorter in the trial group than in the control group (P<0.05). The incidence of internal fixation failure in the trial group (4 cases) was significantly lower than that in the control group (14 cases) (P<0.05). The incidence of femoral neck shortening and the change of neck-shaft angle at 1 year after operation were significantly lower in the trial group than in the control group (P<0.05). The Harris score at last follow-up was significantly higher in the trial group than in the control group (P<0.05). Compared with the partial threaded cannulated screws, the full threaded cannulated compression screws can effectively maintain fracture reduction, avoid femoral neck shortening, and internal fixation failure. It is a better choice for femoral neck fracture.

TERAPIA DE RESTRIÇÃO DO FLUXO SANGUÍNEO APLICADA AO TREINAMENTO ESPORTIVO

ABSTRACT Introduction: Blood flow restriction therapy, also known as KAATSU pressurization training or ischemic exercise training is a controlled method of vascular occlusion combined with resistance training, with the great growth of its research in recent years. Regular strength training, prevention of lean mass loss, and post-operative rehabilitation are some areas in which the therapy has been prominent. It is believed that it can also be beneficial in sports performance. Objective: Study the effects of an intervention with blood flow restriction therapy on athletes during training. Methods: 32 college athletes with more than two years of experience in sports training, free of injuries, and 20±3 years old were volunteers. They were randomly divided into groups A (no pressure), B (training pressure), C (intermittent pressure), D (full compression). Results: The athletes in the no pressurization group, intermittent pressurization group, training pressurization group, and full-time pressurization group showed significant differences (P&lt;0.05). It can be considered that there is a significant difference in the muscular endurance indexes of the athletes in the non-compression group before and after training, while the athletes in the non-compression group achieved a significant increase in muscular endurance after 6 weeks of training Conclusion: Blood flow restriction therapy can effectively enhance the training effect with various strength qualities, and play a role as a promoter of hypertrophy and vascularization. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

A Study on the Application of TensorFlow Compression Techniques to Human Activity Recognition

In the human activity recognition (HAR) application domain, the use of deep learning (DL) algorithms for feature extractions and training purposes delivers significant performance improvements with respect to the use of traditional machine learning (ML) algorithms. However, this comes at the expense of more complex and demanding models, making harder their deployment on constrained devices traditionally involved in the HAR process. The efficiency of DL deployment is thus yet to be explored. We thoroughly investigated the application of TensorFlow Lite simple conversion, dynamic, and full integer quantization compression techniques. We applied those techniques not only to convolutional neural networks (CNNs), but also to long short-term memory (LSTM) networks, and a combined version of CNN and LSTM. We also considered two use case scenarios, namely cascading compression and stand-alone compression mode. This paper reports the feasibility of deploying deep networks onto an ESP32 device, and how TensorFlow compression techniques impact classification accuracy, energy consumption, and inference latency. Results show that in the cascading case, it is not possible to carry out the performance characterization. Whereas in the stand-alone case, dynamic quantization is recommended because yields a negligible loss of accuracy. In terms of power efficiency, both dynamic and full integer quantization provide high energy saving with respect to the uncompressed models: between 31% and 37% for CNN networks, and up to 45% for LSTM networks. In terms of inference latency, dynamic and full integer quantization provide comparable performance.

Numerical investigation of an oil-free liquid-injected screw compressor with ammonia-water as refrigerant for high temperature heat pump applications

• Thermodynamic analysis of liquid injection with varying ammonia-water mixtures. • Model of an oil-free twin screw compressor with injection, leakage, and heat losses. • Injection of lean solution with low ammonia content is best for oil-free compressor. • Injection flow of 10% of compressor's suction flow is enough for full wet compression. • Two injection ports are advantageous to ensure sufficient lubrication and sealing. This study investigates a numerical model of an oil-free twin screw compressor with ammonia-water mixture as refrigerant and liquid injection. The compressor was identified as main constraint to increase the heat sink temperature of absorption-compression heat pump systems past 120 °C. liquid injection can reduce superheating of the vapor during compression, while an existing liquid film can provide lubrication and sealing, enabling oil-free operation. A quasi-one-dimensional numerical model was developed using the Modelica language. It considers the effects of liquid injection flows and injection positions, leakages, heat losses, and variation in ammonia mass fractions. The results revealed a strong influence of occurring internal leakages, varying ammonia mass fractions of the injected solution and changing injection flows and positions on the evolution of temperature, pressure, and compression power. The injection with lower ammonia mass fraction is beneficial for reducing the discharge temperature, discharge pressure and compression power. The increase in injection flow led to a further reduction in the values obtained. Continuous wet compression, which is required for sufficient sealing and lubrication of the compressor, was achieved with injection at 360° at the beginning of the compression phase and an injection rate of about 10% of the compressor’s suction mass flow. By distributing the injection to two injection ports, wet compression can be supported and occurring under-compression and backflow can be reduced.

일본에서의 ｢경비업법｣개정 및 ‘혼잡경비’ 업무검정의 신설에 대한 일고찰

On October 29, 2022, at around 22:15, a large-scale crushing accident occurred in Itaewon, Yongsan-gu, Seoul, with a crowd of 100,000 gathered ahead of the Halloween festival. This accident is the largest human-caused accident in Korea since the sinking of the Sewol ferry in 2014, and the first recorded since the collapse of Sampoong Department Store in 1995 in which 502 people died in a large-scale disaster in downtown Seoul. In the process of investigation by the Special Investigation Headquarters, it is pointed out that the police's poor response made the accident bigger as the cause of the Itaewon disaster. However, on July 21, 2001, from 20:45 to 50 p.m., 11 people suffered from acute respiratory distress syndrome (ARDS) due to full body compression on the Asagiri Pedestrian Bridge in Akashi City, Hyogo Prefecture, Japan. A large-scale accident occurred in which 183 people were killed or injured. Japan has experienced many legal and social changes, such as the revision of the “Guard Service Act” and the establishment of a new “congestion guard” work test, in the wake of the stampede accident. In this paper, the background of Japan's 'Akashi Fireworks Festival Overpass Accident', the cause of the accident, the judgment of the court, and the resulting legal and social changes were examined to examine the implications for Korea.

Specified models in the problems of the deformation of multilayer plates on a rigid foundations

The analysis and estimation of the stress-strain state (SSS) of multilayered plates on a rigid foundation under the action of stationary transverse loading is an urgent task. As its includes the calculations of strength and deformability of various homogeneous and multilayer coatings. This is the calculation of pavement on relatively rigid bridge structures, or on a non-deformable underlying layer, protective multilayer coatings of flat elements of structures of greater rigidity than roofing, parts and more. Combining materials with isotropic and transversely isotropic physical characteristics into a multilayer package allows you to create multifunctional structures. The SSS of such structures, due to their structural heterogeneity and relatively low transverse stiffness of the individual layers, is significantly associated with the influence of transverse shear deformations and transverse compression deformations. Therefore, the problem of refined modeling of SSS plates, which would take into account these types of deformations, is urgent. Based on the decomposition of the SSS plate into flexural and unflexuralcomponents, it is proposed to optimize the design scheme of deformation of a rectangular multilayer plate on a rigid foundation. The essence of optimization is to consider such a calculation scheme of the plate, in which the SSS of the plate would be fully described by only one component, namely the unflexural component of SSS. To do this, instead of the actual design of the multilayer plate, which is deformed without separation from the foundation, it is proposed to consider the design scheme of the plate, which is formed by symmetrical completion relative to the contact surface of the plate with the foundation. In this case, the plate will be bilaterally symmetrically loaded relative to the middle surface of the plate, and the thickness of the plate will double. SSS plate will be unflexural, which greatly simplifies its modeling. For unflexural SSS, a two-dimensional, high-degree iterative approximation, but three-dimensional models of deformation of multilayer rectangular plate on a rigid foundation with isotropic and transverse-isotropic layers are constructed in an elastic formulation.That models takes full account deformationof transverseshearand transverse compression at transverse loading of a plate. By solving the test problems of deformation of isotropic and transversely isotropic plates on a rigid foundation with sliding and rigid contact with the foundation, and comparing the solutions with the exact three-dimensional solutions of these problems obtained by known methods, the accuracy of the proposed refined models is estimated.The limits of admissible parameters of elastic characteristics of transversely isotropic plates for application of the offered models are established.

Simulability of High-Dimensional Quantum Measurements.

We investigate the compression of quantum information with respect to a given set M of high-dimensional measurements. This leads to a notion of simulability, where we demand that the statistics obtained from M and an arbitrary quantum state ρ are recovered exactly by first compressing ρ into a lower-dimensional space, followed by some quantum measurements. A full quantum compression is possible, i.e., leaving only classical information, if and only if the set M is jointly measurable. Our notion of simulability can thus be seen as a quantification of measurement incompatibility in terms of dimension. After defining these concepts, we provide an illustrative example involving mutually unbiased bases, and develop a method based on semidefinite programming for constructing simulation models. In turn we analytically construct optimal simulation models for all projective measurements subjected to white noise or losses. Finally, we discuss how our approach connects with other concepts introduced in the context of quantum channels and quantum correlations.

The influence of full leg-length compression tights during treadmill running at race speed

The aim of the present study was to examine whether full leg-length compression tights modify physiological and kinematic measures during treadmill running at a competitive race pace in moderately trained runners. Thirteen males and five females completed two 15-minute running tests at a speed corresponding to a recent race time wearing compression tights or loose-fitting running shorts. Running economy (RE) was determined by oxygen consumption and carbon dioxide expiration during the final 3 minutes of treadmill running. Muscle oxygenation, skin temperature, heart rate (HR), vertical oscillation, step frequency and ground contact time (GCT) were measured continuously. GCT was shorter with compression compared with control trials ( p = 0.03), however, no differences in RE, muscle oxygenation, vertical oscillation, step frequency, HR or skin temperature were revealed. Despite a shorter GCT with compression tights, the findings suggest that moderately trained runners do not benefit nor limit physiological responses at a competitive race pace.

High capacity reversible data hiding for encrypted images based on full bit-plane compression

To achieve a high embedding capacity (EC) without any distortion in the directly decrypted result, a reversible data hiding in encrypted images (RDH-EI) scheme based on full bit-plane compression (FBPC) is proposed. FBPC is designed to vacate as much room as possible before image encryption. To enrich the adjacent redundancy within the most significant bit (MSB) planes, we use flip prediction on the first MSB and then replace the other MSB planes with the XOR result between that plane and its higher level one successively. Hilbert curve scanning is introduced to reduce the dimensionality of the planes to obtain eight highly redundant bit sequences. Huffman coding is then utilizing to compress the bit sequences. After FBPC, a compressed image is obtained. Stream cipher with self-feedback is adapted to encrypt the image. Additional data could be embedded into the reserved space of the encrypted domain. Compared with existing RDH-EI algorithms, the proposed scheme could have a higher EC with no distortion in the directly decrypted image due to the high compression performance of FBPC. Experimental results on the BOWS-2 and BOSSbass datasets demonstrate that the average EC can reach 3.56 and 3.71 bits per pixel, respectively.

A point prevalence audit of inpatients with leg ulcers eligible for compression therapy in a large university NHS hospital.

Compression therapy is the mainstay of treatment for venous leg ulceration. Several studies have evaluated leg ulcer management and compression in the community. However, little is known about the leg ulcer population and use of compression therapy in the hospital setting, where it is not often part of inpatient care. This study aimed to evaluate the proportion of inpatients with leg ulceration eligible for compression therapy. A point prevalence audit was undertaken using three methods: patient electronic live report; a leg ulcer audit form; and an electronic record search. The following data were retrieved: patient age, sex, primary reason for admission, diabetes, mobility status, history of dementia, Clinical Frailty Scale score and presence of oedema. Ankle-brachial pressure index was measured to determine patients' eligibility for compression therapy. The audit identified 80/931 (8.5%) inpatients as having confirmed, active leg ulceration. A total of 36/80 (45%) inpatients were assessed for eligibility for compression, of whom 25/36 (69.4%) were eligible for full compression, 2/36 (5.6%) reduced compression and 9/36 (25%) were not eligible for compression therapy. The audit demonstrated that a significant proportion of hospital inpatients with leg ulcers were eligible for compression therapy and that this patient population were heterogenous in terms of comorbidity profile, mobility, frailty and dementia, among other factors. Further research is required to explore the most feasible and effective compression options for inpatients with leg ulcers.

Deeply Tensor Compressed Transformers for End-to-End Object Detection

DEtection TRansformer (DETR) is a recently proposed method that streamlines the detection pipeline and achieves competitive results against two-stage detectors such as Faster-RCNN. The DETR models get rid of complex anchor generation and post-processing procedures thereby making the detection pipeline more intuitive. However, the numerous redundant parameters in transformers make the DETR models computation and storage intensive, which seriously hinder them to be deployed on the resources-constrained devices. In this paper, to obtain a compact end-to-end detection framework, we propose to deeply compress the transformers with low-rank tensor decomposition. The basic idea of the tensor-based compression is to represent the large-scale weight matrix in one network layer with a chain of low-order matrices. Furthermore, we propose a gated multi-head attention (GMHA) module to mitigate the accuracy drop of the tensor-compressed DETR models. In GMHA, each attention head has an independent gate to determine the passed attention value. The redundant attention information can be suppressed by adopting the normalized gates. Lastly, to obtain fully compressed DETR models, a low-bitwidth quantization technique is introduced for further reducing the model storage size. Based on the proposed methods, we can achieve significant parameter and model size reduction while maintaining high detection performance. We conduct extensive experiments on the COCO dataset to validate the effectiveness of our tensor-compressed (tensorized) DETR models. The experimental results show that we can attain 3.7 times full model compression with 482 times feed forward network (FFN) parameter reduction and only 0.6 points accuracy drop.

Full compression response of FG-based scaffolds with varying porosity via an effective numerical scheme

The triply periodic minimal surfaces (TPMS) can be employed to realize the variable porosity gradient in different directions and has a great application prospect in the orthopedic implant field. In the present scrutiny, two kinds of gyroid-based TPMS gradient scaffolds (skeletal-gyroid and sheet-gyroid) in different orientations are established and manufactured by utilizing selective laser melting (SLM) technology with Ti-6Al-4V powders. The meshing of the TPMS based on the voxelization loses its surface smoothness and brings the geometric defects of steps. Therefore, an optimized smoothing-tetrahedral mesh strategy (STMS) to finite element analysis (FEA) is proposed to explore the graded scaffolds’ overall deformation response and energy absorption efficiency. The obtained results reveal that the mechanical properties of the samples are slightly altered after heat treatment. The sheet-gyroid (Sh-G) structure has a higher elastic modulus and compressive strength, more stable energy absorption efficiency, and higher total energy absorption compared with the skeletal-gyroid (Sk-G). The fracture morphology of the Sk-G exhibits two distinct regions: a typical dimple of ductile fracture and a brittle fracture characterized by the flow pattern, while the Sh-G samples only demonstrate brittle fractures. The STMS and Johnson-Cook plastic damage model correctly simulated the gradient porous scaffolds’ plastic deformation and failure behavior after yielding. Furthermore, the stress-strain curves of the simulation agree well with the experimental results such that the minimum elastic modulus and yield strength discrepancies in order are 0.5 and 2.8%. The STMS improves the simulation accuracy of the TPMS structure and provides a solid foundation for designing and applying artificial bone scaffolders in the near future.

Causal Contextual Prediction for Learned Image Compression

Over the past several years, we have witnessed impressive progress in the field of learned image compression. Recent learned image codecs are commonly based on autoencoders, that first encode an image into low-dimensional latent representations and then decode them for reconstruction purposes. To capture spatial dependencies in the latent space, prior works exploit hyperprior and spatial context model to build an entropy model, which estimates the bit-rate for end-to-end rate-distortion optimization. However, such an entropy model is suboptimal from two aspects: (1) It fails to capture global-scope spatial correlations among the latents. (2) Cross-channel relationships of the latents remain unexplored. In this paper, we propose the concept of separate entropy coding to leverage a serial decoding process for causal contextual entropy prediction in the latent space. A <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">causal context model</i> is proposed that separates the latents across channels and makes use of channel-wise relationships to generate highly informative adjacent contexts. Furthermore, we propose a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">causal global prediction model</i> to find global reference points for accurate predictions of undecoded points. Both these two models facilitate entropy estimation without the transmission of overhead. In addition, we further adopt a new group-separated attention module to build more powerful transform networks. Experimental results demonstrate that our full image compression model outperforms standard VVC/H.266 codec on Kodak dataset in terms of both PSNR and MS-SSIM, yielding the state-of-the-art rate-distortion performance.

Lower Limb Assessment Related to Vascularity: A Simple Bedside Enabler.

The lower limb is a vulnerable area of the body and often subjected to minor or major trauma. In the presence of underlying systemic disease, especially with comorbidities related to arterial blood supply and simple venous backflow compromise, traumatic injury may trigger an acute lower limb skin injury to become a chronic ulcer.1 Regardless of the cause of skin breakdown, the majority of chronic lower limb wounds often have an underlying venous etiology2 that can be managed successfully with compression therapy.3 However, not all leg wounds present in the same way nor should they be treated equally. The subtle presence of arterial compromise in a predominantly venous etiology may change the appearance of the wound, the pain experience of the patient, and patient adherence to the treatment protocol (mixed venous-arterial etiology).4 Equally challenging may be lower limb edema in the limb of a person with arterial insufficiency who is not eligible for full compression therapy (mixed arterial-venous etiology).5 These mixed clinical presentations often have subtle differences and, if those are missed, clinical outcomes may not be achieved. The importance of interprofessional team involvement in managing challenging wounds that do not heal at the expected rate cannot be emphasized enough.6 Accordingly, the aim of this bedside enabler is to help clinicians recognize different clinical presentations of lower limb ulcers and assessment markers (Table 1). Recognizing these nuances in day-to-day clinical practice will promote correct initiation of adapted intervention protocols, leading to improved patient outcomes. The Table in this Practice Points column includes markers associated with blood flow etiologies of venous, arterial, mixed arterial-venous, mixed venous-arterial, and the combined neuroischemic diabetic foot.Table 1: FACTORS ASSOCIATED WITH DIFFERENT UNDERLYING ETIOLOGIES IN LOWER LIMB WOUNDSBy empowering clinicians to use multiple markers associated with lower leg and ischemic-related foot ulcers, early detection of complex lower limb ulcers with potential healing difficulties can be established from the outset. Clinicians should prioritize the correction of underlying etiologies and form an interprofessional team centered around the patient. Appropriate interventions should be initiated as needed, such as correction of arterial blood supply, smoking cessation, edema control, and weight loss, as well as metabolic control of blood glucose in persons with diabetes. Astute clinical assessment promotes timely wound treatment, lowering cost while improving patient quality of life.