Johannes Kepler University of Linz

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This chapter covers the routing task of finding the physical connection between already-placed devices. The featured routing engine is composed of a congestion-driven wire planner and a gridless detailed router. First, to resolve possible congestions, the engine determines (on a coarse grid) a scenario that provides a rough guide for each net. The detailed router then finds the exact routes by paying attention to these guides. In the following, the modeling of the routing space and its resources will be discussed. This is complemented by the handling of obstacles that are present in the routing space. At the end of this chapter, the wire-planner and detailed router are described in detail.

This chapter covers the results of the developed circuit capture, placement, and routing mechanisms. First, three different simplified test circuits will be introduced, and the results of their capture will be shown. This is followed by the results of the reinforcement learning (RL) and simulated annealing (SA)-based placement engines. For both engines, the evolution of the placement criterion throughout the optimization process will be shown and discussed. Furthermore, a comparison of the two engines regarding their performances will be made. At the end of this chapter, the results of the wire-planning algorithm and the detailed routing of the test circuits will be shown and discussed. For one of the test circuits, the effectiveness of the wire-planning algorithm is described in detail.

This chapter covers the implemented placement engines. First, a reinforcement learning (RL) based approach will be described, followed by a simulated annealing (SA) one. For the RL engine, first the environment-agent interface and the definitions of the rewards, states, and actions will be presented. This is followed by the implementation details of the environment and agent, which include the used RL algorithm and neural network. For the SA engine, the mapping of the placement problem to a rectangle packing problem and the optimization of it by using a Python library will be shown. To find the placement of a hierarchical circuit, a bottom-up approach will be discussed. At the end of this chapter, a legalization process for fixing non-design-rule-compliant placements will be described that is based on a cell sliding strategy.

This chapter looks at ideas and implementation aspects for possible improvements to the design automation flow, intended to provide starting points for a subsequent revision. First, ideas for generalizing the circuit capturing process will be presented, followed by suggestions for improved methods for the process design kit (PDK) and design rule capturing. Then, improvements for the developed placement engines will be discussed, and at the end of the chapter, the routing engine will be addressed.

This chapter covers the handling of the SKY130 process design kit (PDK) design rules, which are necessary to link the layout with a specific technology. First, the capturing of the PDK content will be presented, including the definitions of multiple abstraction levels for a consistent capturing process. That is followed by a description of the interfaces used during the placement and routing stages to query if a design rule is violated. At the end of this chapter, a method to define different interconnection widths will be shown.

This chapter provides the theoretical background of the most prominent algorithms used throughout this book. First, the idea of reinforcement learning (RL) will be presented, followed by an introduction to Markov decision processes, which form the basis of each RL algorithm. Then, two RL algorithms, called Trust Region Policy Optimization (TRPO) and Proximal Policy Optimization (PPO), will be presented. TRPO provides the theory behind PPO, which is used for the placement task. This is followed by the description of a simulated annealing algorithm, which is used besides the PPO algorithm, for solving the placement task. At the end of this chapter, an introduction to the A* algorithm will be presented, which is needed for the routing task.

This chapter covers the implementation details for setting up a circuit for the placement and routing task from a single netlist-file. Such a netlist must follow the SPICE format and be composed of one top-circuit and optional subcircuits. First, the circuit instantiation process will be described, which includes the implementation details of the data structures for devices, nets and circuits. After that, primitive device compositions will be introduced and an annotation mechanism presented, used to detect them in a larger circuit. At the end of this chapter, the data structures and mechanism for capturing the cell views of the devices, generated by the VLSI layout tool Magic, will be presented.

Research on metaphor in organization studies has proliferated over the last 40 years. For most of its history, metaphors have been studied and deployed as linguistic and cognitive ‘resources’ to unpack the complexity of organizations and the environments in which they operate. Reviewing classic papers on the topic published in Organization Studies, we synthesise the key characteristics of past work and informed by our review offer a more multi-dimensional theoretical perspective to channel research into new directions. Our new perspective is premised on leveraging dissonance and multimodality in producing and using metaphors. We demonstrate how such a viewpoint draws new perspectives for scholars and practitioners alike. We highlight some of the implications of centring future thinking from this multidimensional perspective, including new strategies of deploying metaphors to generate potentially path-breaking theories and ways of studying phenomena.

James Batteas, et al., introduce the field of mechanochemistry in “Moving mechanochemistry forward”.

Purpose To quantify the effect of increasing the posterior tibial slope (PTS) on knee kinematics and the resultant medial and lateral meniscal forces. Methods In this controlled laboratory study, a 6 degrees of freedom (DOF) robotic testing system was used to apply external loading conditions to seven fresh‐frozen human cadaveric knees: (1) 200‐N axial compressive load, (2) 5‐N m internal tibial +10‐N m valgus torque and (3) 5‐N m external tibial + 10‐N m varus torque. Knee kinematics and the resultant medial and lateral meniscal forces were acquired for two PTS states: (1) native PTS and (2) increased PTS. Resultant forces in the medial and lateral meniscus were calculated using the principle of superposition. Results In response to 5‐N m external tibial + 10‐N m varus torque, significantly more internal tibial rotation was observed after increasing PTS at 60° ( p = 0.0156) and 90° ( p = 0.0156) flexion. Increasing PTS caused significantly more medial tibial translation from 30° to 90° flexion in response to 5‐N m internal tibial + 10‐N m valgus torque. In response to 5‐N m external tibial + 10‐N m varus torque, the resultant force in the medial meniscus at 60° flexion decreased significantly after increasing PTS (32.8%, p = 0.016). Resultant forces in the lateral meniscus decreased significantly after increasing PTS at 30° (34.5%; p = 0.016) and 90° (29.7%; p = 0.031) flexion in response to 5‐N m internal tibial + 10‐N m valgus torque. Conclusion Increasing PTS in a native knee with intact cruciate ligaments affected 6 DOF knee kinematics and decreased resultant forces in the medial and lateral meniscus by up to 35% in response to combined rotatory loads. Therefore, increasing PTS during high tibial osteotomy in a knee with intact cruciate ligaments does not increase the force carried by the entire meniscus at time zero. Level of Evidence N/A.

Background The role of local infiltration anesthesia (LIA) in knee surgery is significant. LIA can be more potent than a nerve block, but without the downsides. A wide range of agents are used for LIA, including some off-label medications such as dexmedetomidine and ropivacaine. Dexmedetomidine has recently received attention for decreasing demand for anesthetic agents and prolonged effect of anesthesia. The purpose of this study was to demonstrate safety of dexmedetomidine and ropivacaine as LIA. Methods This is a retrospective analysis of 200 patients receiving 300 mg of ropivacaine, 100 µg of dexmedetomidine and 10 mL of saline solution as LIA. Both agents are off-label for this use. The LIA applied prior to skin closure as a pertiarticular block. Major knee surgery was defined as ligament reconstruction of at least one ligament, fracture of the femur and the tibia, knee replacement and osteotomy. We evaluated short-term major side-effects of these agents, and evaluated 30-day complications. Results Included were 77 arthroplasties, 10 fracture fixations, 19 osteotomies, 55 primary and revision ACL, 10 isolated medial patellar femoral ligament reconstructions, 2 ACLs combined with a partial knee arthroplasty, 4 cartilage transplantations and 23 multiligament knee reconstructions. We observed one transitory discoloration after an ACL reconstruction that disappeared by the 48 h mark. We had no 30-day superficial or deep infections. Cardiac or allergic reactions were not observed. Conclusions LIA in a combination of single high-dose ropivacaine and dexmedetomidine is safe in knee surgery. Further studies evaluating pain relief with this LIA combination are needed.

Background and purpose This study evaluates the early clinical performance of the new Artisse Intrasaccular Device (Artisse ISD), a self-expandable intrasaccular flow diverter, for treating wide-necked aneurysms (WNAs). We report initial safety and efficacy outcomes in the first cohort of patients treated with this novel device. Methods Prospective clinical and radiological data were collected for all patients treated with the Artisse ISD at three Austrian neurovascular centers from July 2023 to August 2024. Aneurysm occlusion was assessed using the Raymond-Roy Classification (RR), the O-Kelly-Marotta (OKM) scale, and the Bicêtre Occlusion Scale Score (BOSS). Results In our study 23 patients (60.9% female, median age 62 years) with 23 saccular aneurysms were treated with the Artisse ISD. Nineteen aneurysms (82.6%) were unruptured and located in the anterior circulation. Initial post-procedure angiography revealed incomplete occlusion in all aneurysms, with significant contrast stasis observed (OKM A2/A3). In 16 patients with a minimum of 3 month follow-up, 81.3% of aneurysms demonstrated complete occlusion (RR1), while 6.3% showed neck remnants (RR2), adding up to an adequate occlusion rate of 87.6%. Two asymptomatic thromboembolic events (8.7%) occurred (small diffusion-weighted restrictions on routine postoperative magnetic resonance imaging (MRI)), with no hemorrhagic complications. No device migration or shape modification was observed during follow-up. Conclusion Early clinical experience with the Artisse ISD demonstrates promising safety and efficacy in the treatment of WNAs, with high rates of complete occlusion at 3 month follow-up.

Background The rate of subjective failure after isolated primary posterior cruciate ligament reconstruction (PCL-R) is relatively high, requiring an improved understanding of factors associated with inferior outcomes. Purpose To determine the association between patient and injury-related factors and total (surgical and clinical) failure at 2 years after PCL-R based on data from the Swedish National Knee Ligament Registry (SNKLR) and the Norwegian Knee Ligament Registry (NKLR). Study Design Cohort study; Level of evidence, 3. Methods Patients with primary isolated PCL-R registered between January 1, 2004 (NKLR), or January 1, 2005 (SNKLR), and December 31, 2020, were included. The primary study outcome was the risk of PCL-R failure at the 2-year follow-up, either surgical (≤2 years of index surgery) or clinical (Knee injury and Osteoarthritis Outcome Score [KOOS] Quality of Life subscale [QoL] <44) failure. Risk factors for failure were estimated utilizing univariable and multivariable logistic regression analyses. Results Among the 189 included patients (36.0% from the SNKLR and 64.0% from the NKLR), the rate of 2-year surgical failure was 5.8%, while the rate of clinical failure was 45.0%. Multivariable analysis showed a negative association between the baseline KOOS QoL and the risk of PCL-R failure (OR, 0.74; 95% CI, 0.57-0.97; P = .027). Univariable analysis indicated a positive association between traffic-related injury mechanism and PCL-R failure risk (OR, 3.11; 95% CI, 1.48-6.50; P = .0026), with a further positive association shown in the adjusted (OR, 6.08; 95% CI, 2.00-18.50; P = .0015) and multivariable (OR, 6.11; 95% CI, 2.01-18.55; P = .0014) models. An area under the curve of 0.70 (95% CI, 0.60-0.80) was reported for the final multivariable model, implying at best poor to acceptable ability of the model to estimate PCL-R failure risk based on the variables considered. Conclusion Patients with isolated primary PCL-R had a high (45%) rate of short-term clinical failure, and traffic-related injury was associated with increased odds of failure. No modifiable risk factors were determined as potential predictors of failure. Clinicians treating patients with isolated PCL-R associated with a traffic-related injury mechanism should be aware of a >6-fold increased odds of revision surgery and inferior knee-related quality of life at short-term follow-up.

The unprecedented consequences of the Covid-19 pandemic have raised concerns about the erosion of social cohesion and intensified social unrest, but evidence for such a link and the underlying channels is still lacking. We use a unique combination of nationally representative survey data, event data on social unrest, and data on Covid-19 fatalities and unemployment at a weekly resolution to investigate the forces behind social cohesion and unrest in the context of the strains on public health and the economy due to the pandemic in the USA. The results show that pandemic-related unemployment and Covid-19 fatalities intensified negative emotional stress and led to a deterioration of economic confidence among individuals. The prevalence of negative emotional stress, particularly in economically strained and politically polarized environments, was, in turn, associated with intensified social unrest as measured by political protests. No such link is found for economic perceptions.