General Motors (India)

The present work provides a novel one-step synthesis for nitrogen-doped activated carbon. The excellent performance of the N-doped AC allows its further application in a hybrid-type supercapacitor, which utilizes a combination of the capacitor electrode and a Li-ion battery anode.

New Pt–Ni catalysts were made for PEMFCs with previously unachieved ORR activity and device durability that exceed the DOE 2017 targets for commercialization.

The potential of infrastructureless vehicular ad hoc networks for providing safety and nonsafety applications is quite significant. The topology of VANETs in urban, suburban, and rural areas can exhibit fully connected, fully disconnected, or sparsely connected behavior, depending on the time of day or the market penetration rate of wireless communication devices. In this article we focus on highway scenarios, and present the design and implementation of a new distributed vehicular multihop broadcast protocol, that can operate in all traffic regimes, including extreme scenarios such as dense and sparse traffic regimes. DV-CAST is a distributed broadcast protocol that relies only on local topology information for handling broadcast messages in VANETs. It is shown that the performance of the proposed DV-CAST protocol in terms of reliability, efficiency, and scalability is excellent.

Behavioral studies in humans have shown that bimanual coordination imposes specific demands on the central nervous system that exceed unimanual task control. In the present study we used functional magnetic resonance imaging to investigate the neural correlate of this additional coordination effort, i.e. regions responding more strongly to bimanual movements than inferred from summing up the responses to the unimanual subtasks. Subjects were scanned while performing movements along different directions, either uni- or bimanually. During the bimanual condition, trajectories of movement of the left and right hand were spatially incompatible, such that additional effort was required to break away from intrinsically favored mirror-movements and to integrate movements of both limbs into a new spatial pattern. Our main finding was that the execution of spatially complex bimanual coordination as compared with the unimanual subtasks activated the anterior cingulate cortex (posterior part) as well as the dorso-anterior precuneus. We hypothesize that the anterior cingulate exerts its modulatory effect on other motor areas, such as the primary motor cortex and the supplementary motor area, in order to suppress intrinsically favored coordination tendencies. Conversely, the precuneus is likely to be involved in shifting attention between different locations in space, which was necessary for monitoring the trajectories of the left and right wrist when both limbs moved in parallel. Our findings suggest that the coordination effort during bimanual and perhaps other modes of coordinated behavior is mediated by regions contributing to higher order functions, which form an interface between cognition and action.

<div class="section abstract"><div class="htmlview paragraph">The fuel-ambient mixture in vaporized fuel jets produced by liquid sprays is fundamental to the performance and operation of engines. Unfortunately, experimental difficulties limit the direct measurement of local fuel-ambient mixture, inhibiting quantitative assessment of mixing. On the other hand, measurement of global quantities, such as the jet penetration rate, is relatively straightforward. Simplified models to predict local fuel-ambient mixture have also been developed, based on these global parameters. However, experimental data to validate these models over a range of conditions is needed. In the current work, we perform measurements of jet global quantities such as vapor-phase penetration, liquid-phase penetration, spreading angle, and nozzle flow coefficients over a range of conditions in a high-temperature, high-pressure vessel. Using this data and other quantitative mixing measurements performed by Rayleigh scattering in the vaporized portion of the jet, we compare to an existing variable-radial-profile model for prediction of fuel mixture fraction during the steady period of injection. Results show that spreading angles based on measurement of the most sensitive outer boundary of the jet, by schlieren or Rayleigh-scatter imaging, are needed as inputs to the model to obtain a match between modeled and measured fuel jet penetration rates. By adjusting the model (with spreading angle) to match the measured penetration, the model predictions also produce local mixture fractions that are within the Rayleigh scattering experimental uncertainty. Using this same penetration-matching technique, accurate model predictions of mixture fraction are achieved for a range of ambient densities, fuel injector nozzle shapes, injection pressures, and types of fuels. Additionally, extrapolation of the mixing measurements suggests that a fuel spray has a smaller spreading angle in the near-field and transitions to a larger angle in the far-field jet.</div></div>

In wireless communications, the desired wireless signal is typically decoded by treating the sum of all the other ongoing signal transmissions as noise. In the networking literature, this phenomenon is typically abstracted using a wireless channel interference model. The level of detail in the interference model, evidently determines the accuracy of the results based upon the model. Several works in the networking literature have made use of simplistic interference models, e.g., fixed ranges for communication and interference, the capture threshold model (used in the ns2 network simulator), the protocol model, and so on. At the same time, fairly complex interference models such as those based on the SINR (signal-to-interference-and-noise ratio) have also been proposed and used. We investigate the impact of the choice of the interference model, on the conclusions that can be drawn regarding the performance of wireless networks, by comparing different wireless interference models. We find that both in the case of random access networks, as well as in the case of scheduled networks (where node transmissions are scheduled to be completely conflict-free), different interference models can produce significantly different results. Therefore, a lot of caution should be exercised before accepting or interpreting results based on simplified interference models. Further, we feel that an SINR-based model is the minimum level of detail that should be employed to model wireless channel interference in a networking context.

Recent functional magnetic resonance imaging (fMRI) studies suggest that the control of fingertip forces between the index finger and the thumb (precision grips) is dependent on bilateral frontal and parietal regions in addition to the primary motor cortex contralateral to the grasping hand. Here we use fMRI to examine the hypothesis that some of the areas of the brain associated with precision grips are more strongly engaged when subjects generate small grip forces than when they employ large grip forces. Subjects grasped a stationary object using a precision grip and employed a small force (3.8 N) that was representative of the forces that are typically used when manipulating small objects with precision grips in everyday situations or a large force (16.6 N) that represents a somewhat excessive force compared with normal everyday usage. Both force conditions involved the generation of time-variant static and dynamic grip forces under isometric conditions guided by auditory and tactile cues. The main finding was that we observed stronger activity in the bilateral cortex lining the inferior part of the precentral sulcus (area 44/ventral premotor cortex), the rostral cingulate motor area, and the right intraparietal cortex when subjects applied a small force in comparison to when they generated a larger force. This observation suggests that secondary sensorimotor related areas in the frontal and parietal lobes play an important role in the control of fine precision grip forces in the range typically used for the manipulation of small objects.

<div class="htmlview paragraph">A review and analysis of existing cadaver head impact data has been conducted in this paper. The association of the Head Injury Criterion with experimental cadaver skull fracture and brain damage has been investigated, and risk curves of HIC versus skull fracture and brain damage have been developed. Limitation of the search for the maximum HIC duration to 15ms has been recommended for the proper use of HIC in the automotive crash environment.</div>

This study deals with the development of a programming procedure for the analysis and design of general problems of elastic bodies in contact. The procedure utilizes a simplex-type algorithm. The technique is applied to Hertzian-type contacts, and contacts of beams on elastic foundations. The selection of initial separations in the latter case for the optimal load distribution is considered as an example for the design scheme. The technique gives an effective and relatively inexpensive means of treating this class of problems.

Conventional verification systems, such as those controlling access to a secure room, do not usually require the user to reauthenticate himself for continued access to the protected resource. This may not be sufficient for high-security environments in which the protected resource needs to be continuously monitored for unauthorized use. In such cases, continuous verification is needed. In this paper, we present the theory, architecture, implementation, and performance of a multimodal biometrics verification system that continuously verifies the presence of a logged-in user. Two modalities are currently used--face and fingerprint--but our theory can be readily extended to include more modalities. We show that continuous verification imposes additional requirements on multimodal fusion when compared to conventional verification systems. We also argue that the usual performance metrics of false accept and false reject rates are insufficient yardsticks for continuous verification and propose new metrics against which we benchmark our system.

Abstract The recent advancements of Internet of Things (IoT) embedded systems, wireless networks, and biosensors those have assisted in the rapid development of implanting wearable sensors are reviewed here. The applications of the internet of medical things (IoMT) that has gained major attention as an ecosystem of connected clinical systems, computing systems, and medical sensors geared towards improving the quality of healthcare services are also reviewed here. The 5G based AI technology can revolute the perception of healthcare and lifestyle. In light of the importance of IoT platforms and 5G networks, the purpose of this proposed research work is to identify threats that could undermine the integrity, privacy, and security of IoMT systems. Also, the novel blockchain‐based approaches that can help in improving the confidentiality of IoMT network. It has been discovered that IoMT is vulnerable to various types of attacks, including denial of service (DoS), malware, and eavesdropping attack. In addition, IoMT is exposed to various vulnerabilities, such as security, privacy, and confidentiality. Despite multiple security threats, there are novel cryptographic techniques, such as access control, identity authentication, and data encryption that can help in improving the security and reliability of IoMT devices.

Environmentally beneficial composites can be made by replacing synthetic fibers with various types of cellulosic fibers. Fibers from pine wood, coir, sisal, abaca, coir, etc. are all good candidates. The most important factor in finding good fiber reinforcement in the composites is the strength of adhesion between matrix polymer and fiber. Due to the presence of hydroxyl groups and other polar groups in various constituents of abaca, the moisture absorption is high, which leads to poor wettability and weak interfacial bonding between fibers and the more hydrophobic matrices. Therefore, it is necessary to impart a hydrophobic nature to the fibers by suitable chemical treatments in order to develop composites with better mechanical properties. In the present work, the effect of alkali treatment on the moisture absorption tendency of single abaca fiber was investigated. The results shown that the alkali treated fiber absorbs less moisture than the untreated raw fiber.

This study characterized driver behavior and established a foundation for defining functional performance requirements associated with a Limited Ability Autonomous Driving System (LAADS) – a system capable of automated steering and speed/headway maintenance tasks on freeways, but does not relieve drivers of all driving tasks. The research was designed to examine and reveal potential issues associated with the use of semi-autonomous systems, exploring impacts on willingness to engage in secondary non-driving related tasks, and driver allocation of visual attention while operating under LAADS (ACC and Lane Centering). Results found meaningful differences in the allocation of visual attention across ACC and LAADS driving under situations where drivers were engaged in a secondary task. Overall findings suggest that given a rudimentary, but reliable, LAADS system (one which does not monitor or otherwise restrict behavior) drivers are likely to increase the frequency of secondary task interactions, and engage in risky tasks that are likely to increase extended glances away from the forward roadway.

The paper is concerned with formulation of the gas dynamic conservation equations for the individual species in a non-equilibrium partially ionized gas mixture. As an example, the conservation equations for the electrons and the overall conservation equations are developed for a three component plasma consisting of electrons, singly-ionized positive ions and neutral atoms. Non-elastic collisions are represented by the collisional-radiative decay mechanism of Bates, Kingston & McWhirter (1962a, b). Maxwellian velocity distributions are assumed, but the electrons are allowed to have a temperature different from the heavier particles and to drift relative to them. Particular attention is given to the electron energy balance equation which differs from that used by other investigators.

<div class="htmlview paragraph">With increasingly stringent emissions regulations and concurrent requirements for enhanced engine thermal efficiency, a comprehensive characterization of the automotive gasoline fuel spray has become essential. The acquisition of accurate and repeatable spray data is even more critical when a combustion strategy such as gasoline direct injection is to be utilized. Without industry-wide standardization of testing procedures, large variablilities have been experienced in attempts to verify the claimed spray performance values for the Sauter mean diameter, D<sub>v90</sub>, tip penetration and cone angle of many types of fuel sprays. A new SAE Recommended Practice document, J2715, has been developed by the SAE Gasoline Fuel Injection Standards Committee (GFISC) and is now available for the measurement and characterization of the fuel sprays from both gasoline direct injection and port fuel injection injectors. A primary motivation for the development of the standardized procedures for test configuration, data acquisition, data reduction and reporting was to achieve significant reductions in the test-to-test and laboratory-to-laboratory variabilities of such reported spray data. All of the major areas of fuel injector spray testing and characterization are addressed in detail in the document, including spray imaging, high-resolution patternation and drop sizing by both phase-Doppler interferometry and laser diffraction.</div> <div class="htmlview paragraph">Valuable lessons regarding the definitions and interpretations of commonly-used spray parameters were learned during the development of the J2715 document, and these are presented and discussed. Based upon the five years of committee discussions and consensus decisions, five key recommendations on fuel spray measurement and characterization are made to the worldwide automotive industry. The first, and most important, recommendation is that the Recommended Practices in SAE J2715 be utilized by the spray laboratories of all automotive companies and injector manufacturers in place of the myriad of in-house test protocols that are currently being used.</div> <div class="htmlview paragraph">To evaluate and quantify the efficacy of the new Recommended Practices in J2715, a comprehensive program of round-robin spray characterization tests was designed, and is currently being conducted in the spray testing laboratories of six injector manufacturers and end-users worldwide. This two-year testing protocol will be completed in mid-2008 and will compare the results of in-house testing procedures to those obtained using the J2715 procedures. This round-robin test program is described in detail, and an informative example of the initial test results for the direct-injection spray angle and spray-tip penetration is provided and discussed.</div>

<div class="htmlview paragraph">A new concept for diesel combustion was investigated by means of numerical simulation, engine experiment, and combustion observation in order to realize a simultaneous reduction of NOx and particulate emission. This concept (HiMICS: <u>H</u>omogeneous charge <u>i</u>ntelligent <u>M</u>ultiple <u>I</u>njection <u>C</u>ombustion <u>S</u>ystem) is based on pre-mixed compression ignition combustion combined with multiple injection. Combustion characteristics of HiMICS concept was investigated by comparing with both a standard single injection and a pilot injection. In HiMICS concept, the pre-mixture is formed by a preliminary injection performed during a period from the early stage of the induction stroke to the middle stage of the compression stroke. Modified KIVA-II code was used to predict engine performances and emissions of each injection method. The simulation results show a capability of considerable improvement in the trade-off relation between NOx emissions and fuel consumption of HiMICS.</div> <div class="htmlview paragraph">Engine tests were also carried out to confirm the simulation results using a single cylinder research engine equipped with a common rail injection system. Contrary to the simulation results, the experimental results show that both trade-off relation of HiMICS between NOx emissions and fuel consumption, NOx and smoke emission, becomes worse than those of standard injection or pilot injection in the region of ordinary injection timing. However, on the other hand, HiMICS has an advantage in the fuel consumption and smoke emission in the region where the injection timing is considerably retarded and NOx emission is extremely low. Remaining problems are its high emission level of HC and CO, too early ignition of the pre-mixture, and inadequate homogenization of the pre-mixture.</div>

<div class="htmlview paragraph">A direct injection-gasoline (DI-G) system was applied to a heavy-duty diesel-type engine to study the effects of charge stratification on the performance of premixed compression ignited combustion. The effects of the fuel injection parameters on combustion phasing were of primary interest. The simultaneous effects of the fuel stratification on Unburned Hydrocarbon (UHC), Oxides of Nitrogen (NO<sub>x</sub>), Carbon Monoxide (CO), and smoke emissions were also measured. Engine tests were conducted with altered injection parameters covering the entire load range of normally aspirated Homogeneous Charge Compression Ignited (HCCI) combustion. Combustion phasing tests were also conducted at several engine speeds to evaluate its effects on a fuel stratification strategy.</div>

Advances in physical models, numerical methods, and computational power together have brought large-eddy simulation (LES) to the point where it warrants serious consideration for computing in-cylinder turbulent flows. This article includes: a discussion of LES and how it differs from Reynolds-averaged Navier Stokes (RANS) modeling; motivation for transitioning to LES for in-cylinder flow in IC engines; and quantitative results for two motored engine configurations. Dynamicsubgrid-scale stress models are emphasized, and results from two different numerical approaches are discussed. Compared to RANS, LES requires a low level of empirical input, provides more complete information on in-cylinder flow structure, and makes previously inaccessible phenomena (e. g. , cycle-to-cycle variability) amenable to analysis.

<div class="htmlview paragraph">A generalized analytical model of an airbag inflation system has been developed and integrated into the CAL3D occupant dynamics simulation program. The new model allows for tabular input of mass flow rate and gas temperature to represent the inflator, and it accounts for airbag material stretch and airbag gas leakage. With this new model, the CAL3D program can be applied to evaluate the occupant protection performance of the majority of airbag inflation systems of practical interest. A separate gas dynamics analysis is also developed for generating the mass flow rate and gas temperature data for representing a pyrotechnic inflator, either when a tank test of the actual inflator is available or when a particular inflation characteristic is desired. Validation of the gas dynamics analysis and the new CAL3D airbag inflation model is demonstrated by application to a driver-side airbag system, for which a comparison is presented of the simulation predictions with the results of an actual barrier test.</div>

In 1983, General Motors Corporation (GM) petitioned the National Highway Traffic Safety Administration (NHTSA) to allow the use of the biofidelic Hybrid III midsize adult male dummy as an alternate test device for FMVSS 208 compliance testing of frontal impact, passive restraint systems. To support their petition, GM made public to the international automotive community the limit values that they imposed on the Hybrid III measurements, which were called Injury Assessment Reference Values (IARVs). During the past 20 years, these IARVs have been updated based on relevant biomechanical studies that have been published and scaled to provide IARVs for the Hybrid III and CRABI families of frontal impact dummies. Limit values have also been developed for the biofidelic side impact dummies, BioSID, ES-2 and SID-IIs. The purpose of the original publication was to provide in a single document: 1) a listing of the IARVs for measurements made with the Hybrid III and CRABI families of frontal impact dummies, and for the biofidelic side impact dummies, 2) the biomechanical and/or scaling bases for these IARVs, and 3) a comparison of IARVs and regulatory compliance limits and how they affect restraint design. The purpose for republication is to correct errors in the original publication and update the regulatory compliance limits.