Recent experiments on ultracold atoms in optical lattices have opened a remarkable new window on the dynamics of quantum matter with long-range entanglement. The simplest paradigm of this is the boson superfluid-insulator quantum phase transition in two spatial dimensions. This project will study the theoretical representation of its dynamics by the methods of gauge-gravity duality. A holographic effective field theory method will be developed by comparing the results of computations in...
Topics: DTIC Archive, HARVARD UNIV CAMBRIDGE MA, *QUANTUM THEORY
Topics: DTIC Archive, HARVARD UNIV CAMBRIDGE MA CRUFT LAB, *DIFFRACTION
Topics: DTIC Archive, HARVARD UNIV CAMBRIDGE MA CRUFT LAB, *ELECTROMAGNETIC FIELDS
In the PECASE program, we address another challenge of small-scale flight: energetics. Gliding forward flight potentially alleviates both of these challenges since gliding requires minimal power and forward flight can achieve passive stability (e.g. using a positive wing dihedral). Many insects effectively use gliding modes to extend flight duration - for example. Monarch butterflies travel greater than 50 miles per day during migration and thousands of miles in aggregate. The PECASE program...
Topics: DTIC Archive, HARVARD UNIV CAMBRIDGE MA, *FLIGHT, GLIDE PATH SYSTEMS
The goal of the proposed research effort (Joint PI: Professor Moon-Ho Jo at POSTEC) was to realize integrated nanoscale optoplasmonic devices by leveraging the expertise of Korean and US PIs. Toward this end, we worked on two distinct, yet related, research fronts: (1) fabrication of active photonic/plasmonic devices that are made of nanoscale photonic/plasmonic cavities coupled to quantum emitters, and (2) fabrication of electrically driven photon/plasmonic sources and detectors on chip....
Topics: DTIC Archive, HARVARD UNIV CAMBRIDGE MA, *PHOTONICS, CAVITIES, FABRICATION, NANOMATERIALS,...
Our long-term goal is to improve operational atmospheric and oceanic forecast capability by maximizing forecast accuracy while minimizing observational and computational costs incurred in producing the forecast.
Topics: DTIC Archive, HARVARD UNIV CAMBRIDGE MA, *FORECASTING, ATMOSPHERE MODELS, ESTIMATES, OCEAN MODELS
In this report, we describe a fast deconvolution approach for color images that combines a sparse regularization cost on the magnitudes of gradients with constraints on their direction in color space. We form these color constraints in a way that allows retaining the computationally-efficient optimization strategy introduced in recent deconvolution methods based on half-quadratic splitting. The proposed algorithm is capable of handling a different blur kernel in each color channel, and is used...
Topics: DTIC Archive, HARVARD UNIV CAMBRIDGE MA, *COLOR DISPLAYS, *GRADIENTS, ALGORITHMS, COMPUTER VISION
A summary is presented of existence and uniqueness theorems for the Navier-Stokes equations for incompressible fluids and related equations.
Topics: DTIC Archive, BARRAR, RICHARD B., HARVARD UNIV CAMBRIDGE MA, *FLUIDS, EQUATIONS, INCOMPRESSIBILITY.
We have now tested twelve subjects in an experiment in which we study how objects are identified when seen from an unusual points of view. As noted in earlier quarterly reports, this study will allow us to test a prediction of Kosslyn, Flynn, Amsterdam and Wang (1990); this theory led us to expect processes in the parietal lobe (involved in shifting attention) and in the frontal lobe (involved in formulating hypotheses) to be invoked when subjects identify pictures of object seen from an...
Topics: DTIC Archive, HARVARD UNIV CAMBRIDGE MA DEPT OF PSYCHOLOGY, *SHIFTING, ATTENTION, PICTURES,...
The broad goal of this project is to develop new computational processes for leveraging visual cues for image-based scene understanding, and we seek to achieve this goal through a careful analysis of reflectance, light transport, and imaging. During the past year, we have continued our exploration of micro computer vision systems, meaning those that can accomplish useful visual tasks within the power and size constraints of micro-scale platforms like micro air vehicles and micro sensor nodes....
Topics: DTIC Archive, HARVARD UNIV CAMBRIDGE MA OFFICE FOR RESEARCH CONTRACTS, *COMPUTER VISION,...
Topics: DTIC Archive, HASHIN, ZVI, HARVARD UNIV CAMBRIDGE MA, *ELASTIC PROPERTIES, *MECHANICS, STRESSES,...
Topics: DTIC Archive, DIPRIMA, R. C., HARVARD UNIV CAMBRIDGE MA, *POROSITY, *TIDES, DIFFUSION, ROCK, GEOLOGY
A theoretical and experimental study of multimode operation regimes in quantum cascade lasers (QCLs) is presented. It is shown that the fast gain recovery of QCLs promotes two multimode regimes in QCLs: One is spatial hole burning (SHB), and the other one is related to the Risken-Nummedal-Graham-Haken (RNGH) instability predicted in the sixties. A model that can account for coherent phenomena, a saturable absorber and SHB is developed and studied in detail both analytically and numerically. A...
Topics: DTIC Archive, Capasso, Federico, HARVARD UNIV CAMBRIDGE MA SCHOOL OF ENGINEERING AND APPLIED...
Thornstein Veblen is known as an iconoclast and critic of theory. It is not generally recognized to what extent he in fact evolved theories of his own, theories which were a development of neoclassical economics and precursor of later developments. This paper sketches his theories of the firm, of cyclical fluctuations, and of economic development.
Topics: DTIC Archive, Arrow, Kenneth J, HARVARD UNIV CAMBRIDGE MA, *ECONOMICS, ECONOMIC MODELS, MONEY,...
The general linear theory of thin elastic shells is treated. A set of equations that uniquely embody certain clearly desirable characteristics is derived.
Topics: DTIC Archive, HARVARD UNIV CAMBRIDGE MA, *DEFORMATION, *ELASTIC SHELLS, *STRESSES, *TENSOR...
Topics: DTIC Archive, BRADSHAW, JOHN A., HARVARD UNIV CAMBRIDGE MA CRUFT LAB, *MAGNETRONS, OPERATION,...
Topics: DTIC Archive, Benoit, H., HARVARD UNIV CAMBRIDGE MA GIBBS CHEMICAL LAB, *LIGHT SCATTERING,...
We are developing robust low-magnetic-field implementations of MRI (LFI) focused on brain imaging with two complimentary test scanner systems: electromagnet and permanent magnet based. We are also developing injury-sensitive MRI based on the detection of free radicals associated with injury using the Overhauser effect and subsequently imaging that modified nuclear polarization using low-field MRI (OMRI). Much of the hardware development of the human head LFI test bed systems and the OMRI system...
Topics: DTIC Archive, HARVARD UNIV CAMBRIDGE MA, *MAGNETIC RESONANCE IMAGING, *TRAUMATIC BRAIN INJURIES,...
Topics: DTIC Archive, Hooton, Earnest A, HARVARD UNIV CAMBRIDGE MA, *MILITARY PERSONNEL, *MUSCLES,...
Topics: DTIC Archive, HARVARD UNIV CAMBRIDGE MA LAB OF SOCIAL RELATIONS, *GROUP DYNAMICS, LEADERSHIP,...
This is the first book to describe the physical properties of quantum materials near critical points with long-range many-body quantum entanglement. Readers are introduced to the basic theory of quantum phases, their phase transitions, and their observable properties. This second edition begins with nine chapters, six of them new, suitable for an introductory course on quantum phase transitions, assuming no prior knowledge of quantum field theory. There are several new chapters covering...
Topics: DTIC Archive, HARVARD UNIV CAMBRIDGE MA, *PHASE TRANSFORMATIONS, *QUANTUM THEORY, FERMIONS, GASES,...
The generalized Stirling numbers of the first kind are defined, certain of their basic properties discussed, and tables given for the square grid k 0(1)10 and j 0(1)10 with l - 10(1)10.
Topics: DTIC Archive, Pickard, William F, HARVARD UNIV CAMBRIDGE MA CRUFT LAB, *COMBINATORIAL ANALYSIS,...
Topics: DTIC Archive, BRADSHAW, JOHN A., HARVARD UNIV CAMBRIDGE MA CRUFT LAB, *DIODES, *MAGNETRONS,...
Topics: DTIC Archive, BUDIANSKY, BERNARD, HARVARD UNIV CAMBRIDGE MA, *SHELLS(STRUCTURAL FORMS),...
This is a final report for the IARPA MQCO Spin Qubits team ending in Dec. 2012, when the lead PI, Charles Marcus, moved from Harvard University to University of Copenhagen to direct the Center for Quantum Devices there. The Spin Qubits team comprises experimental and theoretical physicists, and materials scientists, working to realized gate confined multi-qubit systems in GaAs heterostructures. At the completion of the phase covered by this report, two versions of two-qubit systems were in...
Topics: DTIC Archive, HARVARD UNIV CAMBRIDGE MA, *QUANTUM DOTS, COHERENCE, ELECTRONICS, GALLIUM ARSENIDES,...
Topics: DTIC Archive, BARTLETT, PAUL D., RIDD, JOHN H., HARVARD UNIV CAMBRIDGE MA, *IONIZATION, PHENYL...
We are developing robust low-magnetic-field implementations of MRI (LFI) focused on brain imaging with two complimentary test scanner systems: electromagnet and permanent magnet based. We have also developing injury-sensitive MRI based on the detection of free radicals associated with injury using the Overhauser effect and subsequently imaging that modified nuclear polarization using low-field MRI (OMRI). We have been optimizing imaging sequences, image reconstruction, and parallel imaging...
Topics: DTIC Archive, Rosen,Matthew S, HARVARD UNIV CAMBRIDGE MA CAMBRIDGE, MAGNETIC RESONANCE IMAGING,...
Two programs, containing fictitious subject matter, were employed in a study designed to compare the teaching effectiveness (as measured by posttest) of textual material presented (1) as contingencies for responses in a program, or (2) as material upon which responses were not contingent. The content of the programs was identical, and they differed only in that material whose reading was necessary for correct responding in one program was not necessary for correct responding in the other and...
Topics: DTIC Archive, HARVARD UNIV CAMBRIDGE MA, *PROGRAMMED INSTRUCTION, LEARNING, PERFORMANCE(HUMAN),...
The note presents an algorithm for tracing during garbage collection of list structure. It requires only one bit for each level of doubly branching structure traced. Compared to existing trace algorithms, it generally requires less storage -- often, substantially less.
Topics: DTIC Archive, Wegbreit, Ben, HARVARD UNIV CAMBRIDGE MA, *COMPUTER PROGRAMMING, DATA STORAGE...
Topics: DTIC Archive, STORER, JAMES E., HARVARD UNIV CAMBRIDGE MA CRUFT LAB, *ELECTRICAL IMPEDANCE, *LOOP...
Topics: DTIC Archive, MACK, RICHARD B, HARVARD UNIV CAMBRIDGE MA CRUFT LAB, *ANTENNA RADIATION PATTERNS,...
A method is described for the measurement of peak intensity ratios of gas phase microwave absorption lines. Large errors associated with multiple reflections in the waveguide were eliminated by careful design and the use of ferrite isolators. Detector nonlinearities were neutralized by using a precisely calibrated step attenuator allowing both lines involved in a ratio to be displayed with approximately the same amplitude. Means of minimizing additional sources of error are discussed....
Topics: DTIC Archive, Esbitt, Alan S, HARVARD UNIV CAMBRIDGE MA, *MICROWAVE SPECTROSCOPY, MEASUREMENT,...
The work is a study of two topics in the development of an extensible programming language, i.e., a high level language with powerful definitional facilities so designed that the language can be extended and thereby tailored for use in a wide variety of computer applications. The first topic is a theoretical treatment of an extension facility for syntax. It generalizes the notion of context-free grammars to allow the syntax of a language to be a function of its generated strings. It studies the...
Topics: DTIC Archive, Wegbreit, Ben, HARVARD UNIV CAMBRIDGE MA, *PROGRAMMING LANGUAGES, ALGORITHMS,...
A study is made of the step-by-step integration of ordinary differential equations of the first order by means of formulas obtained from the Gregory-Newton backward interpolating formula. Tables of relevant constants are presented.
Topics: DTIC Archive, Pickard, William F, HARVARD UNIV CAMBRIDGE MA CRUFT LAB, *INTEGRATION, *DIFFERENTIAL...
Topics: DTIC Archive, HARVARD UNIV CAMBRIDGE MA CRUFT LAB, *ELECTROMAGNETIC RADIATION, OPTICS, CIRCUITS,...
Colourimetric sensors and indicators are widely used because of their low cost and simplicity. A significant challenge associated with the design of this type of device is that the sensing mechanism must be simultaneously optimised for the sensitivity of the response and a visually perceptible colour change. Structural colour, derived from coherent scattering rather than molecular absorption, is a promising route to colourimetric sensor design because colour shifts are tied to changes in one of...
Topics: DTIC Archive, HARVARD UNIV CAMBRIDGE MA SCHOOL OF ENGINEERING AND APPLIED SCIENCES, *COLORIMETRIC...
This paper provides algorithms for deciding the outcome for various classes of multilayer games of incomplete information. The classes of games which our algorithms are applicable include games not previously known decidable; furthermore, many of our algorithms have asymptotically optimal complexity. We apply our algorithms to provide alternative proofs of upper bounds, and new time-space tradeoffs on the complexity of multilayer alternating machines.
Topics: DTIC Archive, Reif,John, HARVARD UNIV CAMBRIDGE MA, *Game theory, *Decision theory, Algorithms,...
The possibility of significant improvement in the frequency stability of hydrogen masers by operation at cryogenic temperatures ( 1 K) is discussed. The results of the Harvard/SAO collaboration to build and operate a cryogenic hydrogen maser are summarized, and ongoing work to include space-qualified technology in the cryogenic system is described. Finally, a short list is given of scientific applications (on Earth and in space) of a cryogenic hydrogen maser of superior frequency stability.
Topics: DTIC Archive, HARVARD UNIV CAMBRIDGE MA LYMAN LAB OF PHYSICS, *MASERS, STABILITY, SPACEBORNE, LOW...
Initialization, two-spin coherent manipulation, and readout of a three-spin qubit are demonstrated using a few-electron triple quantum dot. The three-spin qubit is designed to allow all operations for full qubit control to be tuned via nearest-neighbor exchange interaction. Fast readout of charge states takes advantage of multiplexed reflectometry. Decoherence measured in a two-spin subspace is found to be consistent with predictions based on gate voltage noise with a uniform power spectrum....
Topics: DTIC Archive, HARVARD UNIV CAMBRIDGE MA DEPT OF PHYSICS, *QUANTUM DOTS, EXCHANGE, INTERACTIONS,...
This thesis uses significant new evidences from the archives of the JFK and LBJ Presidential libraries as well as open primary sources from the U.S. and Korea to shed new light on the Korean involvement in the Vietnam War, the Japan-Korea normalization treaty of 1965 and the connection between the two. Contrary to popular versions of the Korean entry into Vietnam which focus on the economic rationale, this paper argues that security was the principal factor behind Korea's decision. In addition,...
Topics: DTIC Archive, Kim, Jiyul, HARVARD UNIV CAMBRIDGE MA, *DECISION MAKING, WARFARE, VIETNAM, TREATIES,...
Topics: DTIC Archive, STONE, NOEL, HARVARD UNIV CAMBRIDGE MA CRUFT LAB, *DETECTION, *DETECTORS, *ELECTRONIC...
The paper surveys the ways in which recognition of limitations of information available to economic agents affects the workings of the system and the way in which the propositions of economic theory need restatement. The key point is the fact that probability distributions over economic variables are conditional upon signals on other, apparently irrelevant variables; further, this information is differentially available to different individuals and requires resources to acquire and transmit....
Topics: DTIC Archive, Arrow, Kenneth J, HARVARD UNIV CAMBRIDGE MA, *DECISION MAKING, *ECONOMICS,...
Considerable progress has been made during the past year toward achieving the project's main goals of elucidating the representations and processes involved in implicit and explicit memory for novel visual objects. Experiments have been completed or initiated that (a) clarify the effects of structural and functional encoding manipulations on priming and explicit memory, (b) help to specify the nature of the structural representation that underlies priming effects on the object decision task,...
Topics: DTIC Archive, Schacter, Daniel L, HARVARD UNIV CAMBRIDGE MA DEPT OF PSYCHOLOGY,...
Topics: DTIC Archive, ROSENBERG, SANDERS D., HARVARD UNIV CAMBRIDGE MA, *ORGANIC COMPOUNDS,...
This report contains a record of the continuing investigation of various techniques for automatic content analysis, and for the storage and search of structured information. In particular, some storage allocation techniques are examined which are useful in the manipulation of natural language data; a variety of machine programs and experiments are then described for the processing of bibliographic citations; and two models for a completely automatic document retrieval system are outlined.
Topics: DTIC Archive, HARVARD UNIV CAMBRIDGE MA COMPUTATION LAB, *INFORMATION RETRIEVAL, COMPUTER LOGIC,...
A recent issue of Fortune features an article entitled Why Companies Fail. One of the questions it poses is, Why do successful organizations, which once could do no wrong, suddenly begin to lose their way? In answering that question, experts emphasize that one of the key chasms to avoid is a tendency on the part of management to diversify into fields far from the organization's essential core. While there is no danger of our company failing, recent Air Force restructuring included at least one...
Topics: DTIC Archive, HARVARD UNIV CAMBRIDGE MA, *AIRLIFT OPERATIONS, *AIR FORCE, *ORGANIZATIONAL...
Topics: DTIC Archive, TANG, CHARLES C., HARVARD UNIV CAMBRIDGE MA CRUFT LAB, *DIPOLE ANTENNAS, COUPLED...
Topics: DTIC Archive, SCHWINGER, JULIAN, HARVARD UNIV CAMBRIDGE MA CRUFT LAB, *QUANTUM THEORY,...
Topics: DTIC Archive, Benoit, H., HARVARD UNIV CAMBRIDGE MA GIBBS CHEMICAL LAB, *LIGHT SCATTERING,...
Construction details are given for experimental equipment designed to permit measurement of the self and mutual admittances, current distributions along the radiating elements, and far field radiation patterns of small antenna arrays. The antennas are formed by extending the longitudinally slotted inner conductor of a rigid coaxial line beyond a large groundplane while terminating the outer conductor on the ground plane. A small balanced loop probe can be moved along the slot to sample the...
Topics: DTIC Archive, Mack, Richard B, HARVARD UNIV CAMBRIDGE MA CRUFT LAB, *ELECTROMAGNETIC PROBES,...
