Quantum circuit physical design methodology with emphasis on physical synthesis

In our previous works, we have introduced the concept of “physical synthesis” as a method to consider the mutual effects of quantum circuit synthesis and physical design. While physical synthesis can involve various techniques to improve the characteristics of the resulting quantum circuit, we have proposed two techniques (namely gate exchanging and auxiliary qubit selection) to demonstrate the effectiveness of the physical synthesis. However, the previous contributions focused mainly on the physical synthesis concept, and the techniques were proposed only as a proof of concept. In this paper, we propose a methodological framework for physical synthesis that involves all previously proposed techniques along with a newly introduced one (called auxiliary qubit insertion). We will show that the entire flow can be seen as one monolithic methodology. The proposed methodology is analyzed using a large set of benchmarks. Experimental results show that the proposed methodology decreases the average latency of quantum circuits by about 36.81 % for the attempted benchmarks.     

High temperature phase stability and chemical analysis of the highly doped yttria stabilized zirconia with alumina

Short and long term thermal stability of YSZ was studied considering the equilibrium and non-equilibrium phase transformation of YSZ. To improve the long term thermal stability of YSZ, electrical treatment was introduced. Electrical treatment consists of applying electric field into YSZ at high temperatures under a reducing atmosphere. By optimizing the conditions of treatment, electrical resistivity reduced around 40% and thermal stability improved dramatically. These improvements are due to the generation of tetragonal metastable phases. Arguments are put forth to show that electrical treatment induces a relaxation in the lattice. This relaxation is associated with a reduction in lattice tetragonality and replaces the tetragonal grains of YSZ with domain of metastable phases. High resistance of metastable phase to creep deformation and lower electrical resistivity of domains of metastable phases in comparison with tetragonal grains brings about these improvements.     

Nano- and microvoid formation in ultrafine-grained martensitic Fe-Ni-Mn steel after severe cold rolling

Severe cold-rolling was applied on solution annealed Fe-Ni-Mn steel with fully lath martensite structure to obtain ultrafine-grained structure. Field emission scanning electron microscopy and high resolution transmission electron microscopy (HRTEM) were employed to investigate the microstructural evolution after severe cold-rolling. HRTEM images showed the typical deformed structure consisting of lamellar dislocation cell blocks. HRTEM study also revealed strain-induced reverse martensitic transformation (activated during grain refinement). It was assumed that severe plastic deformation route and related deformation mode were responsible for microstructural evolutions. X-ray diffraction (XRD) diagram revealed 7% (volume fraction) reverted austenite after final deformation pass. Moreover, HRTEM images revealed nano-void nucleation at the interface of severely deformed martensite and reverted austenite presumably due to high strain energy of misfit and molar volume difference between the austenite and the martensite. It seems that the coalescence of nano-voids could lead to the formation of microvoids in the microstructure.     

New permeation models for nanocomposite polymeric membranes filled with nonporous particles

In this article, permeation models for nanocomposite polymeric membranes (NCPMs) filled with nonporous particles are discussed and two new models for prediction of effective permeability of NCPMs are proposed. To derive these models, the presence of interfacial layer at the surface of the nanofiller particles as well as the impact of two important phenomena namely creating void volumes and increasing free volume at the interface layer are taken into account. The capability of the models for prediction of reliable results is checked against available experimental data on permeability of NCPMs and is also compared with other presented models for such membranes. The new proposed models show profound superiority over the well known models such as “Bruggeman model in limit” which offers fairly good prediction for NCPMs.     

A hybrid controller based on CPG and ZMP for biped locomotion

Biped locomotion has attracted much attention in recent years. The most successful implemented methods in this area are based on two approaches, central pattern generator (CPG) and zero moment point (ZMP). Unfortunately, neither of these concepts can solely solve the movement challenge completely. In this study, we introduce a hybrid controller to combine the advantages of these methods. The proposed controller is based on two major approaches, CPG and ZMP. This hybrid controller is composed of a trajectory control system and a trajectory generator system. The trajectory control system applied to keep the robot stable uses ZMP as a real time control feedback. The trajectory generator system, which is composed of nonlinear oscillators, generates stable motions. The parameters of CPG are tuned by a new two-stage approach using differential evolution (DE) and bees algorithm (BA). Furthermore, performance of the proposed controller is verified using the robotic simulation software Webots.     

Using metro-on-chip in physical design flow for congestion and routability improvement

Routability, signal integrity and manufacturability are important issues in physical design and congestion reduction is a widely used method for ameliorating these problems in current design methodologies. Besides, routing congestion may create large delays in detoured global wires that can be avoided by congestion reduction. In recent years, asynchronous serial transceivers are proposed for data transmission in network-on-chip systems to improve the performance of global wires. However the asynchronous transceivers have not been used for reducing the congestion and improving the routability in the physical design flow.In this paper, a new methodology is presented in which regular nets are multiplexed by asynchronous serial transceivers in the physical design flow in order to improve routing congestion and design routability. Experimental results show that for attempted benchmarks, the congestion is reduced by 18.97%, the routability is increased by 21.57% on average and total wirelength is decreased up to 9.05%. However, the overhead in power consumption and computation time are 0.12% and 10.01%, respectively, on average.     

Configurable three-way model merging

Software development is a collaborative activity that requires teams of software engineers to cooperate and work in parallel on versions of models. However, model management techniques such as model differencing, merging, and versioning have turned out to be difficult challenges, due to the complexity of operations and graph-like nature of models. Therefore, a well-developed support for model merging process, as well as conflict management, is highly desired. This paper presents a novel process for model merging, called the Epsilon-based Three-way Merging Process (E3MP) process. Model merging is a significant problem where there are different versions of a system model amongst modeler teams. E3MP includes three components implemented into the Epsilon framework. First, modelers can define domain-specific rules that customize the merging process. Second, E3MP enables an automated method for syntactic and semantic conflict detection amongst different versions of the system model. Third, E3MP puts forward a pattern-based approach for conflict resolution. We applied two generic benchmarks to assess conflict detection and resolution capabilities of our approach and carried out an initial scalability evaluation for the model merge with large models and large change sets. The results of our experiments revealed that the proposed process allows generating consistent and semantically correct merged models.     

Mechanical and Tribological Behavior of Powder Metallurgy Processed Aluminum–Graphite Composite

Russian Journal of Non-Ferrous Metals - In this research, the mechanical and tribological behavior of aluminum–graphite (Al–Gr) composite has been investigated in order to determine the...