Tesla Motors

Ambitious policy targets have recently been set in the US to increase the share of battery electric vehicles (BEVs) in new vehicle sales to 50%, supported by the Clean Vehicle tax credit and investment in electric vehicle charging infrastructure, to reduce GHG emissions from the transportation sector. We develop an integrated multi-sector model that accounts for the effects of consumer heterogeneity in the tangible and intangible costs of BEVs and behavioral preferences in influencing vehicle purchase choices, the dynamics of vehicle stock turnover, and the additional emissions from electricity generation induced by EVs to analyze the effectiveness of these policies in achieving their targets and their economic costs. We find that with the projected mix of electricity generation, these policies will increase the share of BEVs in vehicle stock to 20% at most and reduce GHG emissions by 5% (net of the increase in GHG emissions from the electricity sector) in 2030 compared to the baseline. The net present value of the cumulative welfare costs of these policies over 2022–2030, on the transportation and electricity sectors, is $411 Billion (B) and their cumulative GHG abatement is about 0.9 B metric tons (Mg) of CO 2 , implying a welfare cost of abatement of $458 per Mg of CO 2 ; this is several times larger than estimates of the social cost of carbon. Our findings question the efficacy of a single-minded policy focus on the electrification of vehicles to decarbonize the transportation sector and indicate a significant role for a diversified approach that includes advancing low-carbon biofuels that can lower the carbon intensity of driving most vehicles that will continue to require liquid fuels in the coming decades.

The Tesla-built DOJO system is a scalable solution targeted towards machine learning training applications. It is based on the D1 custom compute chip which packs together 354 independent processors, resulting in 362 TFLOPS of compute and 440 MB of internal static random-access memory storage. While maintaining full programmability, DOJO emphasizes distribution of resources and an extremely high bandwidth interconnect, allowing it to scale from small systems all the way to exaFLOP supercomputers.

Both undergraduate students and faculty members face a challenging job market that requires innovative approaches to skill development and research products. Moreover, entrenched approaches to research and education reinforce traditional hierarchies, exclusionary norms, and exploitative practices. This article describes a lab-based pedagogical framework designed to support faculty research goals and student learning and, simultaneously, to attenuate patterns of historical exclusion. This approach leverages evidence-based best practices from experiential education, team-based workflows, an understanding of servant leadership, and “whole-person”–style mentorship models. We find that these tools advance faculty research goals (in terms of both quality and productivity), support student learning in ways beyond traditional undergraduate coursework, and disrupt patterns of historical exclusion. We provide qualitative evidence to support our model and discuss the hurdles and challenges still to be overcome.

Capacitor voltage natural balancing is an attractive feature of flying capacitor multilevel (FCML) converters. However, with the commonly used phase-shifted pulsewidth modulation, the capacitor voltages still can deviate, and active balancing is often required. Although the natural balancing mechanism and its dynamics have been extensively studied in existing literature, some sources that are responsible for capacitor imbalance in engineering practice are still unclear. This article experimentally investigates the origins of the voltage imbalance in practical implementations of such converters. It presents the corresponding circuit analysis as well as solutions that improve balancing. It is shown that the source impedance and the input capacitance can greatly deteriorate capacitor balancing. Moreover, we also demonstrate in theory and with experiments that an FCML converter with an even number of levels inherently has stronger immunity to such disturbance than that with an odd number of levels. It is also found that the gate signal propagation delay mismatch in half-bridge gate drivers can lead to capacitor imbalance, and this problem is addressed by an alternative gate drive power supply design. Finally, the variations of on -state resistance among different switches are found to have a relatively small impact on capacitor voltage balancing.

We observe that between the competitors of technology products, companies such as HP and Xerox or Apple and Google, one competitor (HP and Apple) manages the reverse supply chain to extract value profitably, while the other competitor (Xerox and Google) uses a third-party reverse logistics company to simply recycle consumer returns. In this chapter, we show that, under a given set of supply chain levers, the OEM’s approach to supply chain network design can significantly impact the profitability in the reverse supply chain over the product lifecycle. We propose an integrated multi-period optimization model called the product life cycle optimization model (PLCOM) to design the closed loop supply chain (CLSC) for the OEMs. The PLCOM is a mixed-integer linear program that consists of a demand model based on the extended-Bass’s diffusion model and a pricing model based on a realistic customer willingness to pay (WTP). The PLCOM is applied to a realistic case study using Apple’s iPhone 7 for a product life cycle of 8 years. We show that an integrated approach to designing the supply chain network by the OEMs is more profitable compared to a sequential approach.

Tesla's Full Self Driving (FSD) computer is the world's first purpose-built computer for the highly demanding workloads of autonomous driving. It is based on a new SoC which integrates industry standard components like CPUs, ISP and GPU, together with our custom neural network accelerators. The FSD computer is capable of processing up to 2,300 frames per second, a 21x improvement over Tesla's previous hardware and at a lower cost, and when fully utilized, enables a new level of safety and autonomy on the road.

In this paper, a new analytical method is proposed to estimate eddy currents inside linear conductive materials. The novel closed form formulation takes into account the effects of both the conductor reaction field which dominates at high frequencies as well as the spatially non-homogeneous nature of the magnetic field penetrating the material. Although the model is suitable for most kinds of permanent magnet machines, it is particularly useful for surface mounted permanent magnet machines where both of these phenomena are prominent. The numerical implementation of the proposed model, which consists of a combination of the method of images and 4-D Fourier transform, is presented. The model is then validated against 2-D and 3-D FEM for a simple magnetic circuit, showing good agreement. Finally, the eddy current magnet loss in a surface-mounted permanent magnet synchronous machine is evaluated and results are discussed.

We are proud to bring to you an issue focused on a pertinent topic-new mobility. The term new mobility was coined to represent four pivotal technologies that will change how we move not only ourselves but also our cargo: connected cars, autonomy, shared mobility, and electrification. The acronyms CASE or ACES are often used to convey these traits that new mobility entails.

The paper presents a comprehensive overview of electrical and thermal energy storage technologies but will focus on mid-size energy storage technologies for demand charge avoidance in commercial and industrial applications.Utilities bill customers not only on energy use but peak power use since transmission costs are a function of power and not energy. Energy storage (ES) can deliver value to utility customers by leveling building demand and reducing demand charges. With increasing distributed energy generation and greater building demand variability, utilities have raised demand charges and are even including them in residential electricity bills. This article will present a comprehensive overview of electrical and thermal energy storage technologies but will focus on mid-size energy storage technologies for demand charge avoidance in commercial and industrial applications. Of the ES technologies surveyed, lithium ion batteries deliver the highest value for demand charge reduction especially with systems that have larger power to energy ratios. Current lithium ion ES systems have payback periods below 5 years when deployed in markets with high demand charges.

This paper demonstrates a two-stage implementation of a step-down power factor preregulator design that achieves a high efficiency across the entire universal input voltage range (85-265 V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rms</sub> ) for an offline power supply application. In this implementation, a resonant LLC converter supplies power to a boost converter operating in a continuous conduction mode. A variable frequency multiplier technique is used in a resonant LLC converter stage to provide different dc gains and compress the effective input voltage range. The efficiency performance achieved is flatter and higher than other conventional offline power converter design consisting of a boost power factor correction circuit followed by a resonant LLC converter, whose efficiency tends to drop significantly at low-line input voltages. The proposed circuit allows MOSFETs with lower voltage ratings and better conduction/switching characteristics to be used in both converter stages. Both of the LLC stage and boost circuit can be better optimized due to the compressed operation range and better semiconductor switches. A scaling law of power losses versus breakdown voltage requirement for boost circuit under the condition of the same output power is presented. Experimental results demonstrated a flatter high efficiency performance across a wide input range.

By 2050, it's normal that the total populace will contact 9.2 billion individuals, 34 percent higher than today. A lot of this development will occur in creating nations like India, which has the biggest zone on the planet with arable land for agriculture. To stay aware of rising populaces and wage development, worldwide sustenance generation must increment by 70 percent so as to have the capacity to encourage the world. With help of IoT, control focuses gather and process information continuously to enable ranchers to settle on the best choices as to planting, treating and collecting crops. Sensors set all through the fields are utilized to gauge temperature and stickiness of the dirt and encompassing air. We Propose a Cloud based Irrigation System for better agriculture farming.

The effects of three esters incorporated as co-solvents in 1.2MLiPF6 EC:EMC:DMC (25:5:70 by volume %) electrolyte were studied in Li[Ni1-x-yCoxAly]O2/Graphite-SiO pouch cells. The esters: methyl propionate (MP), ethyl acetate (EA) and methyl butyrate (MB) were compared in a variety of tests on the cells. Storage tests at 60°C at both 4.2 V and 2.5 V demonstrated that MB and MP outperformed EA and cells containing 20% MP showed the least voltage drop during the 500 h storage period. In long-term cycling tests at 40°C, cells containing up to 20% ester exhibited similar capacity retention compared to cells with only EC:EMC:DMC solvent. Unwanted lithium plating could be suppressed in cells with 20% MP during charging above 2C compared to ester-free cells, which showed the onset of unwanted lithium plating at 1.8C. This improvement is due to the increased Li⁺ conductivity of electrolytes containing MP. In addition, the use of up to 40% MP did not enhance reactivity between the charged electrode materials and electrolyte at elevated temperatures according to accelerating rate calorimetry measurements.

Prolonged mechanical loading can lead to the breakdown of skin and underlying tissues which can, in turn, develop into a pressure ulcer. The benefits of pressure relief and/or redistribution to minimise risk have been well documented. Manufacturers have developed alternating air pressure mattresses (APAMs) to provide periodic relief for individuals on prolonged bed-rest. The present study describes the development of a control system, termed Pneumatic Manager which can vary the signature of an APAM, namely its pressure amplitude, cell profile and cycle period. An experimental array was designed to investigate the effects of varying these parameters, particularly with respect to its ability to maintain skin viability in a group of five healthy volunteers lying in a supine position. Transcutaneous gas (TcPO2/TcPCO2) tensions at the sacrum were monitored. In addition, pressures and microclimate parameters at the loaded support interface were also measured. In the majority of test conditions the alternating support produced sacral TcPO2 values, which either remained relatively high or fluctuated in concert with cycle period providing adequate viability. However, in 46% of cases at the extreme pressure amplitude of 100/0 mmHg, there was compromise to the skin viability at the sacrum, as reflected in depressed TcPO2 levels associated with an elevation of TcPCO2 levels above the normal range. In all cases, both the humidity and temperature levels increased during the test period. It is interesting to note that interface pressures at the sacrum rarely exceeded 60 mmHg. Although such studies need to be extended to involve bed-bound individuals, the results provide a design template for the optimum pressure signatures of APAM systems to ensure maintenance of skin viability during pronged loading.

This chapter will introduce and discuss important system-level challenges for software-defined networking (SDN) in fiber wireless networks, particularly in light of recent networking trends such as 5G mobile networks and the Internet of Things (IoT) paradigm. The presented discussion will cover vital aspects from both the control and data plane perspectives. In the data plane, recent fiber wireless trends surrounding the increasingly strong reliance of advanced mobile systems on fiber-optic networks and the emergence of cloud radio access network architectures with fiber-optic links to/from remote wireless cell sites will be covered in particular detail. Specifically, the high-speed, low-latency optical fronthaul architecture will be regarded as the baseline for future fiber wireless networks, and system-level challenges related to signaling formats, network densification and topology, and optical component selection will be considered. Moreover, the requirements for and ramifications of SDN-based control in fiber wireless networks will be examined. A survey of recent R&D advances in SDN for fiber wireless will also be presented. As potential solutions to important system-level challenges, efficient signaling across the optical network, flexibility in the selection of wavelength division multiplexing (WDM)-based optics components, and support for a dynamic physical-layer topology will be highlighted. In terms of network control and management, a centralized, programmable SDN-based control plane is regarded as an attractive approach to bring about a fiber wireless network evolution featuring automated, programmable end-to-end resource orchestration and ultimately a high quality-of-experience (QoE) for end users.

Not every company can afford or is willing to invest in long-term life testing due to time and cost constraints. But such a test can provide very valuable insight about product field behavior during its lifetime. Authors of this paper present a case study on hard disk drive long-term life test data analysis. In order to deal with the non-monotonic hazard rate behavior, the bi-modal mixed life distribution and bi-modal competing failure modeling are applied to fit the time to failure data. The model parameters’ estimation, their physical implications, and field long-term reliability predictions using these two approaches are discussed and compared. The recommendations are given regarding the applicability of each model from an engineering application perspective.

Different battery chemistries perform better on different axes, such as energy density, cost, peak power, recharge time, longevity, and efficiency. Mobile system designers are constrained by existing technology, and are forced to select a single chemistry that best meets their diverse needs, thereby compromising other desirable features. In this paper, we present a new hardware-software system, called Software Defined Battery (SDB), which allows system designers to integrate batteries of different chemistries. SDB exposes application programming interfaces (APIs) to the operating system, which controls the amount of charge flowing in and out of each battery, enabling it to dynamically trade one battery property for another depending on application and/or user needs. Using microbenchmarks from our prototype SDB implementation, and through detailed simulations, we demonstrate that it is possible to combine batteries which individually excel along different axes to deliver an enhanced collective performance when compared to traditional battery packs.

This work presents a series of DNA-structured linear actuators that have high displacements and compact profiles. These actuators operate by twisting and untwisting a double helix that resembles a DNA molecule. Unlike most similarly-motivated twisted string actuators (TSAs), these DNA-structured actuators can have the ability to exert both push and pull forces on a load. Thus, although originally designed for cable-driven robotics, these actuators have the ability to work as part of many different mechatronic systems. Two inherently different actuator designs were investigated, one with straight-line edges (rails) and one with helical rails. Two mathematical models of angular rotation versus linear displacement were developed and simulated, one for each design, and three prototypes were constructed to validate the models. The final prototype was tested for displacement, restorative torque, and pull force characteristics. This last prototype showed a 30.5 cm stroke for a 40.5 cm actuator, or a displacement of 75.3% of its total length. Copyright © 2016 by ASME Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal