Code motion of control structures in high-level languages

Author(s):  
Ron Cytron ◽  
Andy Lowry ◽  
F. Kenneth Zadeck
2020 ◽  
Vol 10 (20) ◽  
pp. 7124
Author(s):  
Anja Babić ◽  
Filip Mandić ◽  
Nikola Mišković

This paper describes the design, development, and testing of both hardware and software for a visual servoing-based system that enables agents within a heterogeneous marine robotic swarm to share energy. The goal of this system is prolonging the active operational time of the swarm as a whole, allowing it to perform long-term environmental monitoring and data collection missions. The implementation presented in the paper features an over-actuated autonomous surface platform docking up to four floating sensor nodes at a time and replenishing their batteries using wireless inductive charging. Mechanical solutions for each robot segment related to the docking procedure are presented, along with pertinent high-level and low-level control structures. A node featuring an extended Kalman filter and additional heuristics is used to fuse measurements from a neural network trained for object detection and a hue thresholding image processing algorithm, in order to track the docking target and achieve visual servoing. Finally, experimental results in both a controlled environment and challenging conditions on-site are presented. Once deployed, the developed system successfully enables the approach and docking of the designated target, showing its feasibility in different real-life conditions.


2021 ◽  
pp. 9-19
Author(s):  
Nikita Zelenchuk ◽  
◽  
Ekaterina Pristavka ◽  
Aleksandr Maliavko ◽  
◽  
...  

The implementation of the new multi-paradigm (functionally- imperative) programming language El, developed at the Department of Computer Science of the Novosibirsk State Technical University, in the form of a compiler is associated with the need to find ways to solve a number of complex problems. The current version of the compiler does implement only partially functionality of the language and generates far from optimal executable codes. In this paper, we consider the problem of an efficient compilation of an El-program, taking into account the need to implement new high-level data structures (two-sided lists, vectors with special forms of access, and a number of others) and control structures of the language, which make it possible to uniformly define cyclic and branching computational processes, as well as those laid down in the language a mechanism for explicitly controlling the mutability of variables. The tasks of improving and developing a compiler organized according to the classical multi-platform scheme are briefly considered, in which the front-end (lexical, syntactic, and semantic analyzers) converts the program to be translated into pseudocode of a single format, and used efficient infrastructure for building LLVM compilers as a back-end that turns pseudocode into executable code for different platforms. Execution of all possible operations on elements of high-level data structures (lists, tuples, vectors), as well as on arbitrary-precision numbers, has been moved to the runtime support library and, accordingly, can be deeply optimized. For this structure, the outlined ways of solving the problem of developing and improving the compiler by deep reforming and optimization of the chain of transformations of the translated program implemented by the front-end are formulated. At the initial stage, it is planned to implement a new compiler for two platforms: Linux and Windows.


Author(s):  
David P. Bazett-Jones ◽  
Mark L. Brown

A multisubunit RNA polymerase enzyme is ultimately responsible for transcription initiation and elongation of RNA, but recognition of the proper start site by the enzyme is regulated by general, temporal and gene-specific trans-factors interacting at promoter and enhancer DNA sequences. To understand the molecular mechanisms which precisely regulate the transcription initiation event, it is crucial to elucidate the structure of the transcription factor/DNA complexes involved. Electron spectroscopic imaging (ESI) provides the opportunity to visualize individual DNA molecules. Enhancement of DNA contrast with ESI is accomplished by imaging with electrons that have interacted with inner shell electrons of phosphorus in the DNA backbone. Phosphorus detection at this intermediately high level of resolution (≈lnm) permits selective imaging of the DNA, to determine whether the protein factors compact, bend or wrap the DNA. Simultaneously, mass analysis and phosphorus content can be measured quantitatively, using adjacent DNA or tobacco mosaic virus (TMV) as mass and phosphorus standards. These two parameters provide stoichiometric information relating the ratios of protein:DNA content.


Author(s):  
J. S. Wall

The forte of the Scanning transmission Electron Microscope (STEM) is high resolution imaging with high contrast on thin specimens, as demonstrated by visualization of single heavy atoms. of equal importance for biology is the efficient utilization of all available signals, permitting low dose imaging of unstained single molecules such as DNA.Our work at Brookhaven has concentrated on: 1) design and construction of instruments optimized for a narrow range of biological applications and 2) use of such instruments in a very active user/collaborator program. Therefore our program is highly interactive with a strong emphasis on producing results which are interpretable with a high level of confidence.The major challenge we face at the moment is specimen preparation. The resolution of the STEM is better than 2.5 A, but measurements of resolution vs. dose level off at a resolution of 20 A at a dose of 10 el/A2 on a well-behaved biological specimen such as TMV (tobacco mosaic virus). To track down this problem we are examining all aspects of specimen preparation: purification of biological material, deposition on the thin film substrate, washing, fast freezing and freeze drying. As we attempt to improve our equipment/technique, we use image analysis of TMV internal controls included in all STEM samples as a monitor sensitive enough to detect even a few percent improvement. For delicate specimens, carbon films can be very harsh-leading to disruption of the sample. Therefore we are developing conducting polymer films as alternative substrates, as described elsewhere in these Proceedings. For specimen preparation studies, we have identified (from our user/collaborator program ) a variety of “canary” specimens, each uniquely sensitive to one particular aspect of sample preparation, so we can attempt to separate the variables involved.


2020 ◽  
Vol 29 (4) ◽  
pp. 738-761
Author(s):  
Tess K. Koerner ◽  
Melissa A. Papesh ◽  
Frederick J. Gallun

Purpose A questionnaire survey was conducted to collect information from clinical audiologists about rehabilitation options for adult patients who report significant auditory difficulties despite having normal or near-normal hearing sensitivity. This work aimed to provide more information about what audiologists are currently doing in the clinic to manage auditory difficulties in this patient population and their views on the efficacy of recommended rehabilitation methods. Method A questionnaire survey containing multiple-choice and open-ended questions was developed and disseminated online. Invitations to participate were delivered via e-mail listservs and through business cards provided at annual audiology conferences. All responses were anonymous at the time of data collection. Results Responses were collected from 209 participants. The majority of participants reported seeing at least one normal-hearing patient per month who reported significant communication difficulties. However, few respondents indicated that their location had specific protocols for the treatment of these patients. Counseling was reported as the most frequent rehabilitation method, but results revealed that audiologists across various work settings are also successfully starting to fit patients with mild-gain hearing aids. Responses indicated that patient compliance with computer-based auditory training methods was regarded as low, with patients generally preferring device-based rehabilitation options. Conclusions Results from this questionnaire survey strongly suggest that audiologists frequently see normal-hearing patients who report auditory difficulties, but that few clinicians are equipped with established protocols for diagnosis and management. While many feel that mild-gain hearing aids provide considerable benefit for these patients, very little research has been conducted to date to support the use of hearing aids or other rehabilitation options for this unique patient population. This study reveals the critical need for additional research to establish evidence-based practice guidelines that will empower clinicians to provide a high level of clinical care and effective rehabilitation strategies to these patients.


2006 ◽  
Vol 175 (4S) ◽  
pp. 260-260
Author(s):  
Rile Li ◽  
Hong Dai ◽  
Thomas M. Wheeler ◽  
Anna Frolov ◽  
Gustavo Ayala

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