620 research outputs found

    Mixed-Signal Neural Network Implementation with Programmable Neuron

    Get PDF
    This thesis introduces implementation of mixed-signal building blocks of an artificial neural network; namely the neuron and the synaptic multiplier. This thesis, also, investigates the nonlinear dynamic behavior of a single artificial neuron and presents a Distributed Arithmetic (DA)-based Finite Impulse Response (FIR) filter. All the introduced structures are designed and custom laid out

    Applications of Reissner's principle to structural dynamics

    Get PDF
    The analysis and prediction of the dynamic behaviour of s7ructural components plays an important role in modern engineering design. :n this work, the so-called "mixed" finite element models based on Reissnen's variational principle are applied to the solution of free and forced vibration problems, for beam and :late structures. The mixed beam models are obtained by using elements of various shape functions ranging from simple linear to complex cubic and quadratic functions. The elements were in general capable of predicting the natural frequencies and dynamic responses with good accuracy. An isoparametric quadrilateral element with 8-nodes was developed for application to thin plate problems. The element has 32 degrees of freedom (one deflection, two bending and one twisting moment per node) which is suitable for discretization of plates with arbitrary geometry. A linear isoparametric element and two non-conforming displacement elements (4-node and 8-node quadrilateral) were extended to the solution of dynamic problems. An auto-mesh generation program was used to facilitate the preparation of input data required by the 8-node quadrilateral elements of mixed and displacement type. Numerical examples were solved using both the mixed beam and plate elements for predicting a structure's natural frequencies and dynamic response to a variety of forcing functions. The solutions were compared with the available analytical and displacement model solutions. The mixed elements developed have been found to have significant advantages over the conventional displacement elements in the solution of plate type problems. A dramatic saving in computational time is possible without any loss in solution accuracy. With beam type problems, there appears to be no significant advantages in using mixed models

    A unified data flow model for fault tolerant computers

    Get PDF
    The Dataflow Simulation System (DFSS) at USL was used as the medium on which a functional simulaton of sIFT was produced. DFSS is written in PL/I and is supported by MULTICS. Within the simulation, all the interprocessor communication, fault simulation, system state data, and monitoring were implemented in dataflow and supported directly by DFSS. The actual processor level computation was carried out by the SIFT code in PASCAL. The interface between DFSS in PL/I and the SIFT code in PASCAL was supported under a mechanism in DFSS called a Node Realization Module (NRM)

    Dry Surface Micromanipulation Using An Untethered And Magnetic Microrobot

    Get PDF
    Precise micromanipulation tasks are typically performed using micromanipulators that require an accessible workspace to reach components. However, many applications have inaccessible or require sealed workspaces. This paper presents a novel magnetically-guided, and untethered, actuation method for precise and accurate positioning of microcomponents on dry surface within a remote workspace using a magnetic microrobot. By use of an oscillatory and uniform magnetic field, the magnetic microrobot can traverse on a dry surface with fine step size and accurate open-loop vector following, 3% and 2% of its body-length, respectively (step size of 7 μm). While maintaining precise positioning capability, the microrobot can manipulate and carry other microcomponents on the dry surface using direct pushing or grasping using various attachments, respectively. We demonstrate and characterize the untethered micromanipulation capabilities of this method using a 3 mm cubic microrobot for us

    Exploring the potential for accelerating sparse matrix-vector product on a Processing-in-Memory architecture

    Get PDF
    As the importance of memory access delays on performance has mushroomed over the past few decades, researchers have begun exploring Processing-in-Memory (PIM) technology, which offers higher memory bandwidth, lower memory latency, and lower power consumption. In this study, we investigate whether an emerging PIM design from Sandia National Laboratories can boost performance for sparse matrix-vector product (SMVP). While SMVP is in the best-case bandwidth-bound, factors related to matrix structure and representation also limit performance. We analyze SMVP both in the context of an AMD Opteron processor and the Sandia PIM, exploring the performance limiters for each and the degree to which these can be ameliorated by data and code transformations. Over a range of sparse matrices, SMVP on the PIM outperformed the Opteron by a factor of 1.82. On the PIM, computational kernel and data structure transformations improved performance by almost 40% over conventional implementations using compressed-sparse row format

    First Report of Intestinal Myiasis Due To Eristalis tenax in Iran

    Get PDF
    Eristalis tenax, belonging to order Diptera, family Syrphidae seldomly causes intestinal myiasis. Intestinal myiasis caused by E. tenax larvae is a rare manifestation found in both humans and other vertebrate animals. We report a 22-year-old woman presented with this myiasis. The larva in her stool sample was identified as E. tenax related to its typical morphology and authentic clues. Lack of specific control measures in the domestic water supply system was the most probable cause of this infestation

    Characterization of the invariable residue 51 mutations of human immunodeficiency virus type 1 capsid protein on in vitro CA assembly and infectivity

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The mature HIV-1 conical core formation proceeds through highly regulated protease cleavage of the Gag precursor, which ultimately leads to substantial rearrangements of the capsid (CAp24) molecule involving both inter- and intra-molecular contacts of the CAp24 molecules. In this aspect, Asp51 which is located in the N-terminal domain of HIV-1 CAp24 plays an important role by forming a salt-bridge with the free imino terminus Pro1 following proteolytic cleavage and liberation of the CAp24 protein from the Pr55Gag precursor. Thus, previous substitution mutation of Asp51 to alanine (D51A) has shown to be lethal and that this invariable residue was found essential for tube formation in vitro, virus replication and virus capsid formation.</p> <p>Results</p> <p>We extended the above investigation by introducing three different D51 substitution mutations (D51N, D51E, and D51Q) into both prokaryotic and eukaryotic expression systems and studied their effects on in vitro capsid assembly and virus infectivity. Two substitution mutations (D51E and D51N) had no substantial effect on in vitro capsid assembly, yet they impaired viral infectivity and particle production. In contrast, the D51Q mutant was defective both for in vitro capsid assembly and for virus replication in cell culture.</p> <p>Conclusion</p> <p>These results show that substitutions of D51 with glutamate, glutamine, or asparagine, three amino acid residues that are structurally related to aspartate, could partially rescue both in vitro capsid assembly and intra-cellular CAp24 production but not replication of the virus in cultured cells.</p
    corecore