Automatic dynamics simplification in Fast Multipole Method: application to large flocking systems

This paper introduces a novel framework with the ability to adjust simulation’s accuracy level dynamically for simplifying the dynamics computation of large particle systems to improve simulation speed. Our new approach follows the overall structure of the well-known Fast Multipole Method (FMM) coming from computational physics. The main difference is that another level of simplification has been introduced by combining the concept of motion levels of detail from computer graphics with the FMM. This enables us to have more control on the FMM execution time and thus to trade accuracy for efficiency whenever possible. At each simulation cycle, the motion levels of detail are updated and the appropriate ones are chosen adaptively to reduce computational costs. The proposed framework has been tested on the simulation of a large dynamical flocking system. The preliminary results show a significant complexity reduction without any remarkable loss in the visual appearance of the simulation, indicating the potential use of the proposed model in more realistic situations such as crowd simulation.     

Effects of pH and sintering temperature on the synthesis and electrical properties of the bilayered LaSr2Mn2O7 manganite prepared by the sol–gel process

The bilayered LaSr₂Mn₂O₇ manganite was synthesized by the sol–gel process at different pH values (3.5, 7, and 9.5) and different sintering temperatures (1553, 1623, and 1723 K) to investigate the effects of growth conditions upon the structural and electrical properties of the samples under investigation. X-Ray diffraction and FT-IR spectroscopy techniques confirm the phase formation for all samples. However, samples sintered at 1553, 1623, and 1723 K, and formed at pH = 7 are single phased having a tetragonal structure. Study of these single-phased samples indicates that with increase in the sintering temperature from 1553 to 1723 K, the average grain size increases from ~200 to ~1000 nm. To investigate the influence of grain size on the conduction mechanism, resistivity of the samples was measured as a function of temperature. The data obtained was analyzed by the adiabatic small polaron hopping model. These analyses show the influence of grain size on the parameters obtained by fitting the data by the above models.     

A novel free format Persian/Arabic handwritten zip code recognition system

In Iran like many other countries, the categorization of postal envelopes is executed manually, mostly based on the handwritten addresses and zip codes. That process is still slow and prone to man-made errors. Therefore, having an automated, accurate and efficient system to recognize handwritten zip codes is of high necessity for a faster and easier arrangement of postal envelopes, and consequently, enhanced performance of the post office.     

Entity resolution for distributed probabilistic data

The problem of entity resolution over probabilistic data (ERPD) arises in many applications that have to deal with probabilistic data. In many of these applications, probabilistic data is distributed among a number of nodes. The simple, centralized approach to the ERPD problem does not scale well as large amounts of data need to be sent to a central node. In this paper, we present FD (Fully Distributed), a decentralized algorithm for dealing with the ERPD problem over distributed data, with the goal of minimizing bandwidth usage and reducing processing time. FD is completely distributed and does not depend on the existence of certain nodes. We validated FD through implementation over a 75-node cluster and simulation using the PeerSim simulator. We used both synthetic and real-world data in our experiments. Our performance evaluation shows that FD can achieve major performance gains in terms of bandwidth usage and response time.     

Fast UV detection and hydrogen sensing by ZnO nanorod arrays grown on a flexible Kapton tape

ZnO nanorod arrays were grown on a flexible Kapton tape using microwave-assisted chemical bath deposition. High crystalline properties of the produced nanorods were proven by X-ray diffraction patterns and field emission scanning electron microscopy. Additionally, the photoluminescence spectrum showed higher UV peaks compared with visible peaks, which indicates that the ZnO nanorods had high quality and low number of defects. The metal-semiconductor-metal (MSM) configuration was used to fabricate UV and hydrogen gas detectors based on the ZnO nanorods grown on a flexible Kapton tape. Upon exposure to 395 nm UV light, the UV device exhibited fast response and decay times of 37 ms and 44 ms, respectively, at a bias voltage of 30 V. The relative sensitivities of the gas sensor made of the ZnO nanorod arrays, at hydrogen concentration of 2 %, at room temperature, 150 °C and 200 °C, are 0.42, 1.4 and 1.75 respectively.     

Auxiliary qubit selection: a physical synthesis technique for quantum circuits

Quantum circuit design flow consists of two main tasks: synthesis and physical design. Addressing the limitations imposed on optimization of the quantum circuit objectives because of no information sharing between synthesis and physical design processes, we introduced the concept of “physical synthesis” for quantum circuit flow and proposed a technique for it. Following that concept, in this paper we propose a new technique for physical synthesis using auxiliary qubit selection to improve the latency of quantum circuits. Moreover, it will be shown that the auxiliary qubit selection technique can be seamlessly integrated into the previously introduced physical synthesis flow. Our experimental results show that the proposed technique decreases the average latency objective of quantum circuits by about 11% for the attempted benchmarks.     

Structural isomers in the perkin reaction. II. Products of interaction of 4-bromophthalic anhydride with phenylacetic acids and some of their reactions

Isomeric bromobenzalphthalides of type 1 were obtained by condensation of 4-bromophthalic anhydride with phenylacetic acids. Isomeric benzalphthalimidines of type 6–11 were also prepared and some of their reactions discussed.