Planning Robust Strategies for Constructing Multi-object Arrangements

A crucial challenge in robotics is achieving reliable results in spite of sensing and control uncertainty. A prominent strategy for dealing with uncertainty is to construct a feedback policy, where actions are chosen as a function of the current state estimate. However, constructing such policies is computationally very difficult. An alternative strategy is conformant planning which finds open-loop action sequences that achieve the goal for all input states and action outcomes. In this work, we investigate the conformant planning approach to robot manipulation. In particular, we tackle the problem of pushing multiple objects simultaneously to achieve a specified arrangement. Conformant planning is a belief-state planning problem. A belief state is the set of all possible states of the world, and the goal is to find a sequence of actions that will bring an initial belief state to a goal belief state To do forward belief-state planning, we created a deterministic belief-state transition model from supervised learning based on physics simulations. A key pitfall in conformant planning is that the complexity of the belief state tends to increase with each operation, making it increasingly harder to compute the effect of actions. This work explores the idea that we can construct conformant plans for robot manipulation by only using actions resulting in compact belief states

Model AI Assignments 2018

The Model AI Assignments session seeks to gather and disseminate the best assignment designs of the Artificial Intelligence (AI) Education community. Recognizing that assignments form the core of student learning experience, we here present abstracts of seven AI assignments from the 2018 session that are easily adoptable, playfully engaging, and flexible for a variety of instructor needs. Assignment specifications and supporting resources may be found at http://modelai.gettysburg.edu

Fast Fully Secure Multi-Party Computation over Any Ring with Two-Thirds Honest Majority

We introduce a new MPC protocol to securely compute any functionality over an arbitrary black-box finite ring (which may not be commutative), tolerating $t<n/3$ active corruptions while \textit{guaranteeing output delivery} (G.O.D.). Our protocol is based on replicated secret-sharing, whose share size is known to grow exponentially with the number of parties $n$. However, even though the internal storage and computation in our protocol remains exponential, the communication complexity of our protocol is \emph{constant}, except for a light constant-round check that is performed at the end before revealing the output. Furthermore, the amortized communication complexity of our protocol is not only constant, but very small: only $1 + \frac{t-1}{n}<1\frac{1}{3}$ ring elements per party, per multiplication gate over two rounds of interaction. This improves over the state-of-the art protocol in the same setting by Furukawa and Lindell (CCS 2019), which has a communication complexity of $2\frac{2}{3}$ \emph{field} elements per party, per multiplication gate and while achieving fairness only. As an alternative, we also describe a variant of our protocol which has only one round of interaction per multiplication gate on average, and amortized communication cost of $\le 1\frac{1}{2}$ ring elements per party on average for any natural circuit. Motivated by the fact that efficiency of distributed protocols are much more penalized by high communication complexity than local computation/storage, we perform a detailed analysis together with experiments in order to explore how large the number of parties can be, before the storage and computation overhead becomes prohibitive. Our results show that our techniques are viable even for a moderate number of parties (e.g., $n>10$)

Electrowetting-on-Dielectric Actuation of a Vertical Translation and Angular Manipulation Stage

Adhesion and friction during physical contact of solid components in microelectromechanical systems (MEMS) often lead to device failure. Translational stages that are fabricated with traditional silicon MEMS typically face these tribological concerns. This work addresses these concerns by developing a MEMS vertical translation, or focusing, stage that uses electrowetting-on-dielectric (EWOD) as the actuating mechanism. EWOD has the potential to eliminate solid-solid contact by actuating through deformation of liquid droplets placed between the stage and base to achieve stage displacement. Our EWOD stage is capable of linear spatial manipulation with resolution of 10 μm over a maximum range of 130 μm and angular deflection of approximately ±1°, comparable to piezoelectric actuators. We also developed a model that suggests a higher intrinsic contact angle on the EWOD surface can further improve the translational range, which was validated experimentally by comparing different surface coatings. The capability to operate the stage without solid-solid contact offers potential improvements for applications in micro-optics, actuators, and other MEMS devices.United States. Office of Naval ResearchNational Science Foundation (U.S.). Graduate Research Fellowship Program (Grant 1122374)National Science Foundation (U.S.) (Major Research Instrumentation Grant for Rapid Response Research (MRI-RAPID)

Project-based, collaborative, algorithmic robotics for high school students: Programming self-driving race cars at MIT

We describe the pedagogy behind the MIT Beaver Works Summer Institute Robotics Program, a new high-school STEM program in robotics. The program utilizes state-of-the-art sensors and embedded computers for mobile robotics. These components are carried on an exciting 1/10-scale race-car platform. The program has three salient, distinguishing features: (i) it focuses on robotics software systems: the students design and build robotics software towards real-world applications, without being distracted by hardware issues; (ii) it champions project-based learning: the students learn through weekly project assignments and a final course challenge; (iii) the learning is implemented in a collaborative fashion: the students learn the basics of collaboration and technical communication in lectures, and they work in teams to design and implement their software systems. The program was offered as a four-week residential program at MIT in the summer of 2016. In this paper, we provide the details of this new program, its teaching objectives, and its results. We also briefly discuss future directions and opportunities

Epidemiology, patterns of care, and mortality for patients with acute respiratory distress syndrome in intensive care units in 50 countries

IMPORTANCE: Limited information exists about the epidemiology, recognition, management, and outcomes of patients with the acute respiratory distress syndrome (ARDS). OBJECTIVES: To evaluate intensive care unit (ICU) incidence and outcome of ARDS and to assess clinician recognition, ventilation management, and use of adjuncts-for example prone positioning-in routine clinical practice for patients fulfilling the ARDS Berlin Definition. DESIGN, SETTING, AND PARTICIPANTS:The Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure (LUNG SAFE) was an international, multicenter, prospective cohort study of patients undergoing invasive or noninvasive ventilation, conducted during 4 consecutive weeks in the winter of 2014 in a convenience sample of 459 ICUs from 50 countries across 5 continents. EXPOSURES:Acute respiratory distress syndrome. MAIN OUTCOMES AND MEASURES: The primary outcome was ICU incidence of ARDS. Secondary outcomes included assessment of clinician recognition of ARDS, the application of ventilatory management, the use of adjunctive interventions in routine clinical practice, and clinical outcomes from ARDS. RESULTS: Of 29,144 patients admitted to participating ICUs, 3022 (10.4%) fulfilled ARDS criteria. Of these, 2377 patients developed ARDS in the first 48 hours and whose respiratory failure was managed with invasive mechanical ventilation. The period prevalence of mild ARDS was 30.0% (95% CI, 28.2%-31.9%); of moderate ARDS, 46.6% (95% CI, 44.5%-48.6%); and of severe ARDS, 23.4% (95% CI, 21.7%-25.2%). ARDS represented 0.42 cases per ICU bed over 4 weeks and represented 10.4% (95% CI, 10.0%-10.7%) of ICU admissions and 23.4% of patients requiring mechanical ventilation. Clinical recognition of ARDS ranged from 51.3% (95% CI, 47.5%-55.0%) in mild to 78.5% (95% CI, 74.8%-81.8%) in severe ARDS. Less than two-thirds of patients with ARDS received a tidal volume 8 of mL/kg or less of predicted body weight. Plateau pressure was measured in 40.1% (95% CI, 38.2-42.1), whereas 82.6% (95% CI, 81.0%-84.1%) received a positive end-expository pressure (PEEP) of less than 12 cm H2O. Prone positioning was used in 16.3% (95% CI, 13.7%-19.2%) of patients with severe ARDS. Clinician recognition of ARDS was associated with higher PEEP, greater use of neuromuscular blockade, and prone positioning. Hospital mortality was 34.9% (95% CI, 31.4%-38.5%) for those with mild, 40.3% (95% CI, 37.4%-43.3%) for those with moderate, and 46.1% (95% CI, 41.9%-50.4%) for those with severe ARDS. CONCLUSIONS AND RELEVANCE: Among ICUs in 50 countries, the period prevalence of ARDS was 10.4% of ICU admissions. This syndrome appeared to be underrecognized and undertreated and associated with a high mortality rate. These findings indicate the potential for improvement in the management of patients with ARDS

The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment

The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since July 2014. This paper describes the second data release from this phase, and the fourteenth from SDSS overall (making this, Data Release Fourteen or DR14). This release makes public data taken by SDSS-IV in its first two years of operation (July 2014-2016). Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey (eBOSS); the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data driven machine learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS website (www.sdss.org) has been updated for this release, and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020, and will be followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14 happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov 2017 (this is the "post-print" and "post-proofs" version; minor corrections only from v1, and most of errors found in proofs corrected

An Integrated Approach to the Prediction of Chemotherapeutic Response in Patients with Breast Cancer

BACKGROUND: A major challenge in oncology is the selection of the most effective chemotherapeutic agents for individual patients, while the administration of ineffective chemotherapy increases mortality and decreases quality of life in cancer patients. This emphasizes the need to evaluate every patient's probability of responding to each chemotherapeutic agent and limiting the agents used to those most likely to be effective. METHODS AND RESULTS: Using gene expression data on the NCI-60 and corresponding drug sensitivity, mRNA and microRNA profiles were developed representing sensitivity to individual chemotherapeutic agents. The mRNA signatures were tested in an independent cohort of 133 breast cancer patients treated with the TFAC (paclitaxel, 5-fluorouracil, adriamycin, and cyclophosphamide) chemotherapy regimen. To further dissect the biology of resistance, we applied signatures of oncogenic pathway activation and performed hierarchical clustering. We then used mRNA signatures of chemotherapy sensitivity to identify alternative therapeutics for patients resistant to TFAC. Profiles from mRNA and microRNA expression data represent distinct biologic mechanisms of resistance to common cytotoxic agents. The individual mRNA signatures were validated in an independent dataset of breast tumors (P = 0.002, NPV = 82%). When the accuracy of the signatures was analyzed based on molecular variables, the predictive ability was found to be greater in basal-like than non basal-like patients (P = 0.03 and P = 0.06). Samples from patients with co-activated Myc and E2F represented the cohort with the lowest percentage (8%) of responders. Using mRNA signatures of sensitivity to other cytotoxic agents, we predict that TFAC non-responders are more likely to be sensitive to docetaxel (P = 0.04), representing a viable alternative therapy. CONCLUSIONS: Our results suggest that the optimal strategy for chemotherapy sensitivity prediction integrates molecular variables such as ER and HER2 status with corresponding microRNA and mRNA expression profiles. Importantly, we also present evidence to support the concept that analysis of molecular variables can present a rational strategy to identifying alternative therapeutic opportunities

Clinical Characterization of Patients Diagnosed with Prostate Cancer and Undergoing Conservative Management:A PIONEER Analysis Based on Big Data

Background: Conservative management is an option for prostate cancer (PCa) patients either with the objective of delaying or even avoiding curative therapy, or to wait until palliative treatment is needed. PIONEER, funded by the European Commission Innovative Medicines Initiative, aims at improving PCa care across Europe through the application of big data analytics. Objective: To describe the clinical characteristics and long-term outcomes of PCa patients on conservative management by using an international large network of real-world data. Design, setting, and participants: From an initial cohort of &gt;100 000 000 adult individuals included in eight databases evaluated during a virtual study-a-thon hosted by PIONEER, we identified newly diagnosed PCa cases (n = 527 311). Among those, we selected patients who did not receive curative or palliative treatment within 6 mo from diagnosis (n = 123 146). Outcome measurements and statistical analysis: Patient and disease characteristics were reported. The number of patients who experienced the main study outcomes was quantified for each stratum and the overall cohort. Kaplan-Meier analyses were used to estimate the distribution of time to event data. Results and limitations: The most common comorbidities were hypertension (35–73%), obesity (9.2–54%), and type 2 diabetes (11–28%). The rate of PCa-related symptomatic progression ranged between 2.6% and 6.2%. Hospitalization (12–25%) and emergency department visits (10–14%) were common events during the 1st year of follow-up. The probability of being free from both palliative and curative treatments decreased during follow-up. Limitations include a lack of information on patients and disease characteristics and on treatment intent. Conclusions: Our results allow us to better understand the current landscape of patients with PCa managed with conservative treatment. PIONEER offers a unique opportunity to characterize the baseline features and outcomes of PCa patients managed conservatively using real-world data. Patient summary: Up to 25% of men with prostate cancer (PCa) managed conservatively experienced hospitalization and emergency department visits within the 1st year after diagnosis; 6% experienced PCa-related symptoms. The probability of receiving therapies for PCa decreased according to time elapsed after the diagnosis.</p

Clinical Outcomes With a Repositionable Self-Expanding Transcatheter Aortic Valve Prosthesis: The International FORWARD Study

Background Clinical outcomes in large patient populations from real-world clinical practice with a next-generation self-expanding transcatheter aortic valve are lacking. Objectives This study sought to document the clinical and device performance outcomes of transcatheter aortic valve replacement (TAVR) with a next-generation, self-expanding transcatheter heart valve (THV) system in patients with severe symptomatic aortic stenosis (AS) in routine clinical practice. Methods The FORWARD (CoreValve Evolut R FORWARD) study is a prospective, single-arm, multinational, multicenter, observational study. An independent clinical events committee adjudicated safety endpoints based on Valve Academic Research Consortium-2 definitions. An independent echocardiographic core laboratory evaluated all echocardiograms. From January 2016 to December 2016, TAVR with the next-generation self-expanding THV was attempted in 1,038 patients with symptomatic, severe AS at 53 centers on 4 continents. Results Mean age was 81.8 ± 6.2 years, 64.9% were women, the mean Society of Thoracic Surgeons Predicted Risk of Mortality was 5.5 ± 4.5%, and 33.9% of patients were deemed frail. The repositioning feature of the THV was applied in 25.8% of patients. A single valve was implanted in the proper anatomic location in 98.9% of patients. The mean aortic valve gradient was 8.5 ± 5.6 mm Hg, and moderate or severe aortic regurgitation was 1.9% at discharge. All-cause mortality was 1.9%, and disabling stroke occurred in 1.8% at 30 days. The expected-to-observed early surgical mortality ratio was 0.35. A pacemaker was implanted in 17.5% of patients. Conclusions TAVR using the next-generation THV is clinically safe and effective for treating older patients with severe AS at increased operative risk. (CoreValve Evolut R FORWARD Study [FORWARD]; NCT02592369