3DGates: An Instruction-Level Energy Analysis and Optimization of 3D Printers

Conference
Jerry Ajay, Chen Song, Aditya Singh Rathore, Chi Zhou, Wenyao Xu
ASPLOS 17

As the next-generation manufacturing driven force, 3D printing technology is having a transformative effect on various industrial domains and has been widely applied in a broad spectrum of applications. It also progresses towards other versatile fields with portable battery-powered 3D printers working on a limited energy budget. While reducing manufacturing energy is an essential challenge in industrial sustainability and national economics, this growing trend motivates us to explore the energy consumption of the 3D printer for the purpose of energy efficiency. To this end, we perform an in-depth analysis of energy consumption in commercial, off-the-shelf 3D printers from an instruction-level perspective. We build an instruction-level energy model and an energy profiler to analyze the energy cost during the fabrication process. From the insights obtained by the energy profiler, we propose and implement a cross-layer energy optimization solution, called 3DGates, which spans the instruction-set, the compiler and the firmware. We evaluate 3DGates over 338 benchmarks on a 3D printer and achieve an overall energy reduction of 25%.

Don't Forget Your Electricity Bills!: An Empirical Study of Characterizing Energy Consumption of 3D Printers

Workshop
Jerry Ajay, Aditya Singh Rathore, Chen Song, Chi Zhou, Wenyao Xu
APSys 16

3D printing is an emerging technique in product manufacturing. Its applications have been expanding vastly in homebased production. Compared to traditional manufacturing techniques, such as Computerized Numeric Control (CNC) machine tools, it is believed that 3D printing is more cost effective in fabricating personalized products. The product cost estimation in 3D printing mainly takes material expenditure into account, and extensive studies have been performed for reducing filament expense or development of recyclable filaments. However, electricity expenditure is another inevitable cost in the 3D printing process yet an omitted factor in the cost estimation. To this end, this paper introduces the first in-depth study to understand the energy consumption in 3D printing. Specifically, our study comprises of two parts. The first part quantifies both material and electricity use in the 3D printing, and find that the electricity takes up to 32% of the total cost. The second part characterizes the energy consumption and identifies the sensitivity of various parameters.We also share insights and potential solutions to optimize the power consumption of 3D printers.

A portable and cost-effective upper extremity rehabilitation system for individuals with upper limb motor deficits

Conference
Feng Lin, Jerry Ajay, Jeanne Langan, Lora Cavuoto, Ifeoma Nwogu, Heamchand Subryan, Wenyao Xu
Wireless Health 16

Long-term rehabilitation opportunities are critical for millions of individuals with chronic upper limb motor deficits striving to improve their motor performance through self-managed rehabilitation programs. However, there is minimal professional support of rehabilitation across the lifespan. In this paper, we introduce an upper extremity rehabilitation system, the Quality of Movement Feedback-Oriented Measurement System (QM-FOrMS), by integrating cost-effective portable sensors and clinically verified motion quality analysis towards individuals with upper limb motor deficits. Specifically, QM-FOrMS is comprised of an eTextile pressure sensitive mat, named Smart Mat, a sensory can, named Smart Can, and a mobile device. A personalizable and adaptive upper limb rehabilitation program is developed, including both unilateral and bilateral functional activities which can be selected from a list or custom designed to further tailor the program to the individual. Quantitative evaluation of the motor performance from the QM-FOrMS is derived from fine-grained kinematic measurements. We ran a pilot study with three groups, including five baseline subjects (i.e., healthy young adults), six older adults and four individuals with movement impairment. The experimental results show that QM-FOrMS can provide the detailed feature during the unattended rehabilitation exercise, and proposed metrics can distinguish the evaluation results across group.

The evolution and functional impact of human deletion variants shared with archaic hominin genomes

Journal
Yen-Lung Lin, Pavlos Pavlidis, Emre Karakoc, Jerry Ajay, Omer Gokcumen
Molecular Biology and Evolution, Jan. 2015

Allele sharing between modern and archaic hominin genomes has been variously interpreted to have originated from ancestral genetic structure or through non-African introgression from archaic hominins. However, evolution of polymorphic human deletions that are shared with archaic hominin genomes has yet to be studied. We identified 427 polymorphic human deletions that are shared with archaic hominin genomes, approximately 87% of which originated before the Human–Neandertal divergence (ancient) and only approximately 9% of which have been introgressed from Neandertals (introgressed). Recurrence, incomplete lineage sorting between human and chimp lineages, and hominid-specific insertions constitute the remaining approximately 4% of allele sharing between humans and archaic hominins. We observed that ancient deletions correspond to more than 13% of all common (>5% allele frequency) deletion variation among modern humans. Our analyses indicate that the genomic landscapes of both ancient and introgressed deletion variants were primarily shaped by purifying selection, eliminating large and exonic variants. We found 17 exonic deletions that are shared with archaic hominin genomes, including those leading to three fusion transcripts. The affected genes are involved in metabolism of external and internal compounds, growth and sperm formation, as well as susceptibility to psoriasis and Crohn’s disease. Our analyses suggest that these “exonic” deletion variants have evolved through different adaptive forces, including balancing and population-specific positive selection. Our findings reveal that genomic structural variants that are shared between humans and archaic hominin genomes are common among modern humans and can influence biomedically and evolutionarily important phenotypes.