177,887 research outputs found
Small passenger car transmission test: Mercury Lynx ATX transmission
The testing of a Mercury Lynx automatic transmission is reported. The transmission was tested in accordance with a passenger car automatic transmission test code (SAE J65lb) which required drive performance, coast performance, and no load test conditions. Under these conditions, the transmission attained maximum efficiencies in the mid-ninety percent range both for drive performance test and coast performance tests. The torque, speed, and efficiency curves are presented, which provide the complete performance characteristics for the Mercury Lynx automatic transmission
The NATO III 5 MHz Distribution System
A high performance 5 MHz distribution system is described which has extremely low phase noise and jitter characteristics and provides multiple buffered outputs. The system is completely redundant with automatic switchover and is self-testing. Since the 5 MHz reference signals distributed by the NATO III distribution system are used for up-conversion and multiplicative functions, a high degree of phase stability and isolation between outputs is necessary. Unique circuit design and packaging concepts insure that the isolation between outputs is sufficient to quarantee a phase perturbation of less than 0.0016 deg when other outputs are open circuited, short circuited or terminated in 50 ohms. Circuit design techniques include high isolation cascode amplifiers. Negative feedback stabilizes system gain and minimizes circuit phase noise contributions. Balanced lines, in lieu of single ended coaxial transmission media, minimize pickup
Contributors to Success on the Automotive Service Excellence (ASE) Student Certification Exam
This study sought to identify which elements contribute to success on the Automotive Service Excellence (ASE) Student Certification exam. Students at an eastern U.S. technical college who completed all of their automotive major courses and the ASE Student Certification exam during the spring 2017 semester were selected for the study. The results of this study revealed that there was a direct correlation between performance in Physics, Algebra, and Trigonometry 1 and performance on the ASE Student Certification exam. It was also revealed that students who were required to participate in remedial math and/or remedial reading courses were likely to perform at a lower level than their counterparts on the exam. Students who participated in a secondary automotive Career and Technical Education (CTE) program were also likely to perform at a lower level than their counterparts. The results of this study would be useful to administrators and faculty in postsecondary automotive preparation programs
The STRESS Method for Boundary-point Performance Analysis of End-to-end Multicast Timer-Suppression Mechanisms
Evaluation of Internet protocols usually uses random scenarios or scenarios
based on designers' intuition. Such approach may be useful for average-case
analysis but does not cover boundary-point (worst or best-case) scenarios. To
synthesize boundary-point scenarios a more systematic approach is needed.In
this paper, we present a method for automatic synthesis of worst and best case
scenarios for protocol boundary-point evaluation.
Our method uses a fault-oriented test generation (FOTG) algorithm for
searching the protocol and system state space to synthesize these scenarios.
The algorithm is based on a global finite state machine (FSM) model. We extend
the algorithm with timing semantics to handle end-to-end delays and address
performance criteria. We introduce the notion of a virtual LAN to represent
delays of the underlying multicast distribution tree. The algorithms used in
our method utilize implicit backward search using branch and bound techniques
and start from given target events. This aims to reduce the search complexity
drastically. As a case study, we use our method to evaluate variants of the
timer suppression mechanism, used in various multicast protocols, with respect
to two performance criteria: overhead of response messages and response time.
Simulation results for reliable multicast protocols show that our method
provides a scalable way for synthesizing worst-case scenarios automatically.
Results obtained using stress scenarios differ dramatically from those obtained
through average-case analyses. We hope for our method to serve as a model for
applying systematic scenario generation to other multicast protocols.Comment: 24 pages, 10 figures, IEEE/ACM Transactions on Networking (ToN) [To
appear
Evaluation of thermo-oxidized Jatropha bio-oil in lubrication of actual wet clutch materials
In this work, an assessment of the performance of thermo-oxidated Jatropha oil as a lubricant for actual wet clutch materials was performed and compared with a commercial automatic transmission fluid. For this, Jatropha oil, a commercial automatic transmission fluid and a blend of 20 vol% Jatropha oil–80 vol% automatic transmission fluid were subjected to thermo-oxidative aging at 26 °C and 100 °C, followed by a pin-on-disk testing with disk samples from an actual wet clutch. Evaluation of the film thickness at the sliding interface resulted in a boundary lubrication regime for all the tests. The changes in oxidation, viscosity, and a viscosity index of the samples were evaluated along with friction coefficients at various sliding speeds. Jatropha oil was the most sensitive to thermo-oxidation. Jatropha oil and the blend showed a higher viscosity increase than automatic transmission fluid with thermo-oxidation, while the viscosity index of all oils was decreased considerably, Jatropha oil and the blend being the most reduced. Finally, the anti-shudder property, as measured by the change in the friction coefficient with a sliding speed, of Jatropha oil and automatic transmission fluid was improved by thermo-oxidation at 26 °C but worsened at 100 °C, meanwhile it was barely affected in the blend. Therefore, these results indicate that using pure Jatropha oil as automatic transmission fluid would be unsuitable, but blending it with automatic transmission fluids in specific proportions may be apposite for improving the friction properties of wet clutches even under thermo-oxidative conditions
AxonDeepSeg: automatic axon and myelin segmentation from microscopy data using convolutional neural networks
Segmentation of axon and myelin from microscopy images of the nervous system
provides useful quantitative information about the tissue microstructure, such
as axon density and myelin thickness. This could be used for instance to
document cell morphometry across species, or to validate novel non-invasive
quantitative magnetic resonance imaging techniques. Most currently-available
segmentation algorithms are based on standard image processing and usually
require multiple processing steps and/or parameter tuning by the user to adapt
to different modalities. Moreover, only few methods are publicly available. We
introduce AxonDeepSeg, an open-source software that performs axon and myelin
segmentation of microscopic images using deep learning. AxonDeepSeg features:
(i) a convolutional neural network architecture; (ii) an easy training
procedure to generate new models based on manually-labelled data and (iii) two
ready-to-use models trained from scanning electron microscopy (SEM) and
transmission electron microscopy (TEM). Results show high pixel-wise accuracy
across various species: 85% on rat SEM, 81% on human SEM, 95% on mice TEM and
84% on macaque TEM. Segmentation of a full rat spinal cord slice is computed
and morphological metrics are extracted and compared against the literature.
AxonDeepSeg is freely available at https://github.com/neuropoly/axondeepsegComment: 14 pages, 7 figure
The Silent Voice of Those Who are no Longer: Transgenerational Transmission of Information from the Perspective of the Informational Model of Consciousness
The “nature or nurture” problem concerning the debate on the innate features with respect to the
acquired ones is approached in terms of information, from the perspective of the Informational Model
of Consciousness. This model reveals seven distinct informational systems reflected in consciousness as
informational centers, i.e. memory (Iknow-Ik), decisional info-operational center (Iwant-Iw), emotions
(Ilove-Il), metabolic operations (Iam-Ia), genetic transmission (Icreate-Ic), genetic info-generation
(Icreated-Icd) and the anti-entropic center (Ibelieve-Ib). Ib is a life-assisting beneficial center, because
it is opposed to the entropic action of matter, eliminating or reducing the uncertainty characteristic of
unknown possibilities to certainty, and inducing in this way the trust and confidence in own actions.
The pro and contra arguments of the “nature or nurture” are shortly presented, noting the large range of
divergent opinions and concepts on the approached problem. It is shown that the information concept
acting both as informal and matter-related information, specifically referred to the embodiment/
disembodiment mechanisms for the transmission of information during the epigenetic processes, can
coherently approach and explain the transgenerational transmission of the traits acquired during the life
span of the predecessors. The concepts of tendency, affinity, propensity, predisposition, aptitude, vocation
and talent, specific for inheritable properties described by Icd are discussed, pointing out the large pallet
and variety of such concepts describing the evidences detected by external observers on the inherited
behaviors, and that of self-perceived by the implicated individual, as a silent voice of whose are no
longer. The external manifestation of such inherited features and traits depends on practice, because the
characteristic operation of the nervous system and of epigenetic processes is based on repetition and/or
intensive practice, but these are permanently guided by the silent voice of those who are no longer, with
various signal intensities
Operating injection lasers by fast square current pulses of variable amplitude
A simple solid state circuit was used to drive GaAs injection lasers by fast (∼100 nsec) square pulses of variable amplitude (0–25 A). The amplitudes of the current pulses and the corresponding emitted light pulses were measured by a dual peak detector circuit. Using these circuits we were able to plot automatically the current vs light curve and determine the threshold current of the laser diodes
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