Andrew C. Carlson

• M.I.T.--PhD. / HARVARD--PhD
• Chief of Nuclear Radiology at State University of New York @ Stony Brook

Intended for medical students studying the evaluation and diagnosis of heart arrhythmias, the beating heart arrhythmia simulator combines visual, auditory, and tactile stimuli to enhance the student's retention of the subtle differences between various conditions of the heart necessary for diagnosis. Unlike existing heart arrhythmia simulators, our...

Whereas people learn many different types of knowledge from diverse experiences over many years, and become better learners over time, most current machine learning systems are much more narrow, learning just a single function or data model based on statistical analysis of a single data set. We suggest that people learn better than computers precis...

The advantages of utilizing the polymeric shape memory effect for deterministic assembly of microscale objects are explored in this paper. Assembly of building blocks, referred to as inks, by transfer printing is performed using a polymeric stamp with reversible adhesion as a manipulator. The dynamic rigidity control of a shape memory polymer (SMP)...

Whereas people learn many different types of knowledge from diverse experiences over many years, most current machine learning systems acquire just a single function or data model from just a single data set. We propose a never-ending learning paradigm for machine learning, to better reflect the more ambitious and encompassing type of learning perf...

Whereas people learn many different types of knowledge from diverse experiences over many years, most current machine learning systems acquire just a single function or data model from just a single data set. We propose a never-ending learning paradigm for machine learning, to better reflect the more ambitious and encompassing type of learning perf...

We present a specially designed materials chemistry that provides ultrathin adhesive layers with persistent tacky surfaces in solid, nonflowable forms for use in transfer printing and related approaches to materials and micro/nanostructure assembly. The material can be photocured after assembly, to yield a robust and highly transparent coating that...

Microtransfer printing is a versatile process for retrieving, transferring, and placing nanomembranes of various materials on a diverse set of substrates. The process relies on the ability to preferentially propagate a crack along specific interfaces at different stages in the process. Here, we report a mechanics-based model that examines the facto...

Active, programmable control of interfacial adhesion is an important, desired feature of many existing and envisioned systems, including medical tapes, releasable joints, and stamps for transfer printing. Here a design for an elastomeric surface that offers switchable adhesion strength through a combination of peel-rate dependent effects and actuat...

Transfer printing represents a set of techniques for deterministic assembly of micro-and nanomaterials into spatially organized, functional arrangements with two and three-dimensional layouts. Such processes provide versatile routes not only to test structures and vehicles for scientific studies but also to high-performance, heterogeneously integra...

Mobile robots are often proposed as a favorable substitute to human correspondence in emergency response, disaster relief, and environmental monitoring scenarios. In this work, the next iteration of the Aquapod is proposed as a method to facilitate collection of subsurface liquid samples in order to assess toxicity levels in a body of water. This a...

Transfer printing is an important technique for assembling micro/nanomaterials on unusual substrates, with promising applications in the fabrication of stretchable and flexible electronics designed for use in areas such as biomedicine. The process involves retrieval of structures (e.g., micro-devices) from their growth (donor) substrate via an elas...

Information and Communication Technologies (ICTs) play a key role in starting and operating small-scale businesses. In Soweto, South Africa, mobile phones have sparked the creation of new business models and strategies among entrepreneurs. Their use is shown to help maintain relationships and build trust between businesses and clients, thus contrib...

Microscale elastomeric relief structures with “pedestal” shapes provide enhanced operation in stamps designed for deterministic materials assembly via transfer printing. Experimental measurements of adhesion and finite element analysis both show that for certain geometries, exceptionally large enhancements in adhesion strength (over 15×) can be ach...

In this paper we present mechanics and materials aspects of elastomeric stamps that have angled features of relief on their surfaces, designed to enable control of adhesion strength by peeling direction, in a way that can be exploited in schemes for deterministic assembly by transfer printing. Detailed mechanics models capture the essential physics...

We present a micromanufacturing method for constructing microsystems, which we term ‘micro-masonry’ based on individual manipulation, influenced by strategies for deterministic materials assembly using advanced forms of transfer printing. Analogous to masonry in construction sites, micro-masonry consists of the preparation, manipulation, and bindin...

This paper demonstrates the use of a flexible instrumented stamp to enable automated micro transfer printing as a route to large-area, deterministic assembly of microstructured device components or ‘inks’. The ability to instrument the stamp, a critical component for retrieval and placement of a micro device, to detect contact and monitor localized...

We present a novel platform for three dimensional (3D) photonics. A double layer 1×12 multimode interference (MMI) coupler is fabricated using transfer printing of silicon nanomembranes. Optical tests confirm low insertion loss and uniform outputs.

This paper reports the deterministic assembly of microscale silicon objects which are thick (>10 μm) and of arbitrary shape using the elastomeric microtipped stamps. The deterministic assembly consists of the preparation and manipulation of microscale silicon objects. This micromanufacturing strategy, influenced by the microtipped stamp based trans...

The Dark Energy Survey (DES) is a project with the goal of building, installing and exploiting a new 74 CCD-camera at the Blanco telescope, in order to study the nature of cosmic acceleration. It will cover 5000 square degrees of the southern hemisphere sky and will record the positions and shapes of 300 million galaxies up to redshift 1.4. The sur...

By pressure-controlled surface contact area, reversible adhesion can be achieved with strengths tunable by 3 orders of magnitude. This capability facilitates robust transfer printing of active materials and devices onto any surface for the development of stretchable and/or curvilinear electronics. The most important parameter in designing the surfa...

This letter describes the physics and application of an approach to transfer printing that utilizes targeted shear loading to modulate stamp adhesion in a controlled and repeatable fashion. Experimental measurements of pull-off forces as functions of shear and stamp dimension reveal key scaling properties and provide a means for comparison to theor...

As mobile robots decrease in size so does their ability to traverse rough terrain. New forms of locomotion beyond the basic wheel are being explored to overcome this fault. This paper expands on the mechanical design of a previous robot with a high mobility-to-size ratio. To accomplish high mobility the robot uses tumbling as its form of locomotion...

Negative-index metamaterials (NIMs) are engineered structures with optical properties that cannot be obtained in naturally occurring materials. Recent work has demonstrated that focused ion beam and layer-by-layer electron-beam lithography can be used to pattern the necessary nanoscale features over small areas (hundreds of µm(2)) for metamaterials...

The goal of our project is to build a system for inferring the quality of facts and patterns (rules) gathered by a bootstrap learning system, with the aid of a human labeler in an active learning setting. There are two main parts to our project: to construct a general (probably probabilistic) framework for confidence scoring and to utilize active l...

Applications of ferroelectric ceramics, ranging from components for sensors, memory devices, microelectromechanical systems, and energy convertors, all involve planar and rigid layouts. The brittle nature of such materials and their high-temperature processing requirements limit applications to devices that involve only very small mechanical deform...

A mechanics model is developed for the contact radius of stamps with pyramid tips in transfer printing. This is important to the realization of reversible control of adhesion, which has many important applications, such as climbing robots, medical tapes, and transfer printing of electronics. The contact radius is shown to scale linearly with the wo...

Intended for medical students studying the evaluation and diagnosis of heart arrhythmias, the beating heart arrhythmia simulator combines visual, auditory, and tactile stimuli to enhance the student's retention of the subtle differences between various conditions of the heart necessary for diagnosis. Unlike existing heart arrhythmia simulators, our...

A low cost, high flux, large area solar simulator has been designed, built and characterized for the purpose of studying optical melting and light absorption behavior of molten salts. Seven 1500W metal halide outdoor stadium lights are used as the light source to simulate concentrating solar power (CSP) heliostat output. Metal halide bulbs and ball...

At the request of Congress, the National Academy of Sciences convened a series of coordinated activities to provide advice on actions and strategies the nation can take to respond to climate change. This suite of activities included a study on strategies for limiting the magnitude of future climate change (i.e. mitigation). Limiting climate change...

In this article, the authors present and discuss the fabrication of three-dimensional 3D optical phased array OPA devices for large angle, two-dimensional optical beam steering. Fabrication of a single layer one-dimensional OPA prototype for one-dimensional beam steering on silicon nanomembrane is presented. The authors present different approaches...

Reversible control of adhesion is an important feature of many desired, existing, and potential systems, including climbing robots, medical tapes, and stamps for transfer printing. We present experimental and theoretical studies of pressure modulated adhesion between flat, stiff objects and elastomeric surfaces with sharp features of surface relief...

We consider here the problem of building a never-ending language learner; that is, an intelligent computer agent that runs forever and that each day must (1) extract, or read, information from the web to populate a growing structured knowledge base, and (2) learn to perform this task better than on the previous day. In particular, we propose an app...

Process-induced variations and sub-threshold leakage in bulk-Si technology limit the scaling of SRAM into sub-32 nm nodes. New device architectures are being considered to improve control and reduce short channel effects. Among the likely candidates, FinFETs are the most attractive option because of their good scalability and possibilities for furt...

Background: Surgical site infections (SSIs) occur in up to 11.6% of surgeries, lengthening hospital stays and incurring additional costs. Surgical antiseptic solutions vary in the rates of SSIs and their impact on a hospital or surgical center’s budget. Objective: The purpose of this study was to estimate the net budget impact of three antise...

We consider the problem of semi-supervised learning to extract categories (e.g., academic fields, athletes) and relations (e.g., PlaysSport(athlete, sport)) from web pages, starting with a handful of labeled training examples of each category or relation, plus hundreds of millions of unlabeled web documents. Semi-supervised training using only a fe...

We consider here the problem of building a never-ending language learner; that is, an intelligent computer agent that runs forever and that each day must (1) extract, or read, information from the web to populate a growing structured knowledge base, and (2) learn to perform this task better than on the previous day. In particular, we propose an app...

The dramatic deglaciation climate evolution provides a key observation for studying the role of ocean circulation on deglacial CO2 rise and for testing climate models. Here, we present the first transient climate simulation of the deglaciation evolution from the last glacial maximum to the early Holocene in a synchronously coupled general circulati...

The analytical solution is obtained for a semi-infinite linear elastic solid with a sinu-soidal, "wavy" surface profile subject to applied strain. The amplitude A of a deformed wavy surface is related to the initial amplitude A(0) and the applied strain epsilon(a) through the simple expression A=A(0)(1 - epsilon(a)). This relation is confirmed inde...

Increased process variability presents a major challenge for future SRAM scaling. Fast and accurate validation of SRAM read stability and writeability margins is crucial for estimating yield in large SRAM arrays. Conventional SRAM read/write metrics are characterized through test structures that are able to provide limited hardware measurement data...

A key question regarding the future of the semantic web is “how will we acquire structured information to populate the semantic web on a vast scale?” One approach is to enter this information manually. A second approach is to take advantage of pre-existing databases, and to develop common ontologies, publishing standards, and reward systems to make...

This letter describes the physics and application of an approach to transfer printing that uses stamps with microstructures of relief embossed into their surfaces. Experimental measurement of velocity-dependent adhesive strength as a function of relief geometry reveals key scaling properties and provides a means for comparison to theoretical expect...

We present a first synchronously coupled atmosphere-ocean general circulation model (CCSM3) to simulate the well-documented evolution of global climate from the Last Glacial Maximum (LGM) 21,000 years ago to the time of the abrupt Bølling-Allerød (BA) warming 14,500 years ago. Our model reproduces the major features of the deglacition evolution, in...

While gazetteers can be used to perform named entity recognition through lookup-based methods, ambiguity and incomplete gazetteers lead to relatively low recall. A sequence model which uses more general features can achieve higher recall while maintaining reasonable precision, but typically requires expensive annotated training data. To circumvent...

We report research toward a never-ending language learning system, focusing on a first implementation which learns to classify occurrences of noun phrases according to lexical categories such as "city" and "uni- versity." Our experiments suggest that the accuracy of classifiers produced by semi-supervised learning can be improved by coupling the le...

We consider semi-supervised learning of information extraction methods, especially for extracting instances of noun categories (e.g., 'athlete,' 'team') and relations (e.g., 'playsForTeam(athlete,team)'). Semi- supervised approaches using a small number of labeled examples together with many un- labeled examples are often unreliable as they frequen...

Variation in the critical dimension (CD) of a transistor is a primary concern for advanced lithography. Because variation from sources such as corner rounding or line edge roughness does not scale with CD, variability in transistor performance increases with scaling and may impact the timing or even the functionality of critical circuits such as st...

The Atlantic-to-Pacific water vapor transport across Central America has been postulated to play an important role in the overturning circulation of the Atlantic Ocean (Schmittner et al., 2000). Paleoceanographic data suggest that the delta18Osw, and presumably salinity, of western Pacific surface waters has decreased over the course of the Holocen...

This is a report of the first transient simulation of global climate change from the Last Glacial Maximum to 14 kyr BP employing the synchronously coupled NCAR CCSM3. Forced by realistic orbital influences, greenhouse gas concentrations, continental ice sheets, as well as a reasonable characterization of melting water forcing, CCSM3 is able to simu...

Increasing process variability is slowing SRAM scaling by reducing both read and write margins. Existing techniques to compensate for systematic variations optimize cell stability with excessive penalty to writeability. To maximize overall yield, a sensor circuit is presented that optimizes the read / write tradeoff in the presence of process, volt...

We consider the problem of extracting structured records from semi-structured web pages with no human supervision required for each target web site. Previous work on this problem has either required significant human effort for each target site or used brittle heuristics to identify semantic data types. Our method only requires annotation for a few...

Distributions of read and write noise margins in large CMOS SRAM arrays are investigated by directly measuring the bit-line current during bitline / wordline (write) or cell supply (read) voltage sweep in a 768 Kb 45 nm CMOS SRAM test-chip. Good correlation between write/read margin estimates through the bit-line measurements and the DC read SNM (R...

Multi-gate devices are expected to enable continued scaling beyond the 32nm node in part due to their improved gate control of the channel versus planar MOSFETs. Static random access memory (SRAM) scaling, which requires increasing design margins despite decreasing layout area, may motivate the transition to a multi-gate architecture. Tri-gate bulk...

Atomistic 3D device simulations of 20nm-gate-length planar vs. tri-gate bulk MOSFETs with identical nominal retrograde-well and source/drain doping profiles show that the tri-gate structure is more robust to random dopant fluctuation (RDF) effects, i.e. threshold voltage (V_TH) lowering and variation. V_TH lowering is verified t...

This letter presents experimental, numerical, and analytical studies of Au thin films on elastomeric substrates of poly(dimethylsiloxane) that are designed with sinusoidal, “wavy” features of surface relief. Such systems can be useful as stretchable conductors in electronic or sensory devices. The maximum film strain is obtained in terms of film an...

The question of how the human brain represents conceptual knowledge has been debated in many scientific fields. Brain imaging studies have shown that different spatial patterns of neural activation are associated with thinking about different semantic categories of pictures and words (for example, tools, buildings, and animals). We present a comput...

We study methods of efficiently leveraging massive textual corpora through n-gram statistics. Specifically, we explore algorithms that use a database of frequency counts for sequences of tokens in a teraword Web corpus to correct spelling mistakes and to extract a list of instances of some category given only the name of the target category. For sp...

Variation in the critical dimension (CD) of a transistor is a primary concern for advanced lithography. Because variation from sources such as corner rounding or line edge roughness does not scale with CD, variability in transistor performance increases with scaling and may impact the timing or even the functionality of critical circuits such as st...

We study the problem of correcting spelling mistakes in text using memory-based learning techniques and a very large database of token n-gram occurrences in web text as training data. Our approach uses the context in which an error appears to select the most likely candidate from words which might have been intended in its place. Using a novel corr...

We provide a theoretical analysis of the chance accuracies of large collections of clas- siers. We show that on problems with small numbers of examples, some classier can per- form well by random chance, and we derive a theorem to explicitly calculate this accu- racy. We use this theorem to provide a prin- cipled feature selection criterion for spa...

Multiphase dynamics and its characteristics for two-phase gas-liquid flow have been investigated by means of advanced numerical simulations. Although important in many engineering applica- tions, methods for robust and accurate simulations for high density and viscosity ratios remain elusive. A comprehensive comparison of two state-of-the-art Compu...

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Negative-bias temperature instability (NBTI) has been identified as a problem for static random-access-memory (SRAM) reliability since variations in the PMOS threshold voltages have been shown to correlate with rising V_min over time. The effect is greater than what would be expected from the relatively low sensitivity of the static-noise...

This article is an analysis of the characteristics of exogenous endoscopy-related infections, pseudoinfections, and toxic reactions that have occurred worldwide during the period 1974 - 2004. A systematic review of the scientific literature published between 1966 and 2004 was conducted in Medline and the Food and Drug Administration Reports databas...

Unobtrusive educational assessment is a means of measuring student progress using the byproducts of authentic learning activities. It is difficult to perform well. Using a new technology based on graphical models, unobtrusive assessment can become more practical. We describe how we apply our techniques in teaching image processing to undergraduates...

Due to the intrinsic connection between the mechanical properties of carbon nanotubes and their long-ranged interactions, an accurate description for both covalent and van der Waals forces is desired in nanomechanical studies. A tight-binding treatment offers an accurate description for the covalent bonding but fails to account for the long-ranged...

In this work, the impact of this pass-gate feedback (PGFB) technique on cell write-ability is examined, and gate workfunction (Phi_m) tuning for optimization of the trade-off with read margin is discussed. To further improve cell write-ability, the p-channel pull-up devices can also be operated in BG mode, with their back gates driven by...

Chemical erosion of carbon via hydrocarbon formation is investigated by spectroscopic particle flux measurements and with Langmuir probes in the outer Divertor II of the ASDEX Upgrade tokamak. The measurements are made about 10 cm above the strike point of the separatrix at the vertical target plate for hydrogen ion flux densities up to 1023 m-2 s-...

The objective of this study was to analyze the characteristics and costs of exogenous endoscopy-related infections, pseudo-infections, and toxic reactions in the US. A systematic review of the scientific literature published between 1966 and 2005 was conducted in Medline. Data collection was based on a prospective protocol developed by the authors....

The aim of this work is to present recent results of photon efficiency (D/XB) measurements and chemical erosion yields of hydrocarbons in the region of the outer divertor of ASDEX Upgrade. In order to study the influence of plasma edge parameters on the photon efficiencies and therefore on the evaluation of the erosion yield, different hydrocarbons...

OBJECTIVE: Aims: To estimate the cost effectiveness of treatment with peginterferon alfa-2b plus ribavirin compared with interferon alfa-2b plus ribavirin for initial treatment of patients with chronic hepatitis C. METHODS: Individual patient level data from a randomised clinical trial with peginterferon plus rib-avirin were applied to a Markov mod...

abstracts,the logical relation between,the alerts in order to support,automatic,correlation of those alerts involved,in the same,intrusion. The basic building,block of the model,is a logical formula called a capability. We use capability to abstract,consistently,and precisely,all levels of accesses obtained,by the attacker,in each step of a multist...

Proxies of deepwater formation show that a large reduction in the Atlantic meridional overturning circulation (AMOC) occurred at the start of the Younger Dryas event, suggesting that the attendant loss of ocean heat transport caused Younger Dryas cooling in the North Atlantic region. The trigger of this ocean response remains unclear, however, with...

Significant progress has been made on ASDEX Upgrade during the last two years in the basic understanding of transport, in the extension of the improved H-mode in parameter space and towards an integrated operating scenario and in the development of control methods for major performance limiting instabilities. The important features were the underst...

High energy (MeV), heavy ion irradiation can be used as a tool to deform patterned SiO2 films in a controlled fashion. We have used this technique to deform micron-sized holes in SiO2 films generated by photolithography and focused ion beam milling. The holes were fabricated in 2 mum thick SiO2 films in the size range from 500 nm to 2 mum and were...

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Nevus lipomatosus is a rare connective tissue nevus characterized by mature adipose tissue within the dermis. An 11-year-old boy presented with an eyelid papule that had been observed expectantly since birth and had exhibited gradual and progressive enlargement. Excisional biopsy revealed a polypoid mass formed of mature adipocytes within the dermi...

Recent results from the ASDEX Upgrade experimental campaigns 2001 and 2002 are presented. An improved understanding of energy and particle transport emerges in terms of a 'critical gradient' model for the temperature gradients. Coupling this to particle diffusion explains most of the observed behaviour of the density profiles, in particular, the fi...

Our research is founded on the idea that ubiquitous, non-intrusive, concept-centric student assessment is an important way for teachers to gain insight into the educational needs of their students. Ubiquitous assessment means that assessment is an integral part of students' everyday activities, thus allowing for a detailed temporal understanding of...

Relaxation oscillations found in the divertor of the ASDEX Upgrade tokamak by means of spectroscopy and probe diagnostics are reported. They are observed in both electron density and temperature with frequencies in the range from 45 to 80 Hz. In the line emission they are detected in C III, but not in Dalpha light. Interpretation of the experimenta...

Objective To identify which factors are considered important for eating habits and weight change in obese participants in a one-year weight reduction programme at a primary health care centre. Design A qualitative study of factors affecting participants' eating habits and weight change before, during and after the programme. Settiiig The primary he...

High density operation in the ASDEX Upgrade divertor I with horizontal target plates is reported. Density rampup experiments were carried out to characterize detached plasma conditions in the divertor. During the detached phases, hydrogen continua and spectral line emission from high-n shells were observed in the divertor due to the volume recombin...

The closed ASDEX Upgrade Divertor II, `LYRA', is capable of handling heating powers of up to 20 MW or P/R of 12 MW/m, owing to a reduction of the maximum heat flux to the target plates by more than a factor of 2 compared with the open Divertor I. This reduction is caused by high radiative losses from carbon and hydrogen inside the divertor region a...

In 1997 the new `LYRA' divertor went into operation at ASDEX Upgrade and, in parallel, the neutral beam heating power was increased to 20 MW by installation of a second injector leading to a P/R value of 12 MW/m. Experiments have shown that the ASDEX Upgrade LYRA divertor is capable of handling such high heating powers. There is an overall reductio...