The propagation of heat pulses in zigzag and armchair double wall nanotubes (DWNTs) has been investigated using molecular dynamics simulations. It is found that the leading heat wave packets in zigzag (9,0)∕(18,0) an...
The propagation of heat pulses in zigzag and armchair double wall nanotubes (DWNTs) has been investigated using molecular dynamics simulations. It is found that the leading heat wave packets in zigzag (9,0)∕(18,0) and armchair (5,5)∕(10,10) DWNTs move with the speed of longitudinal acoustic (LA) phonon modes. The intensities of the leading heat wave packets in outer and inner shells in DWNTs were found to be five to seven times larger than that of the corresponding single wall nanotubes (SWNTs). The heat energy carried by the leading heat wave packets in zigzag DWNT was about four and five times more than those in armchair DWNT shells. Within the leading LA wave packet, the strain in the inner shell of the DWNTs is stronger than the strain in the outer shell and considerably larger than strain in the corresponding SWNTs. The regions with the largest strain coincide with the regions of high kinetic temperatures within the LA mode wave packets. The higher energy of the LA mode waves in DWNT shells compared to SWNT is attributed to the presence of higher strain fields in DWNTs compared to individual SWNTs. The higher strain in the inner shell of DWNT compared to the outer shell accounts for the three to five times higher kinetic energy of leading wave packets in inner shells compared to those in outer shells. The induced strain fields in zigzag DWNT are distributed over a wider region compared to armchair DWNT, and the strains in inner and outer shells of zigzag DWNT are out phase by 180°.
This paper presents a novel modular climbing caterpillar named ZC-I. After a related survey on the topic, a systematical summarizing on basic functions provided by this system is given. ZC-I features fast-building mec...
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This paper presents a novel modular climbing caterpillar named ZC-I. After a related survey on the topic, a systematical summarizing on basic functions provided by this system is given. ZC-I features fast-building mechanical structure and low-frequency vibrating passive attachment principle. Active joints actuated by RC servos endow the connecting modules with the ability of changing shapes in two dimensions. After that the discussion focuses on the various locomotion capabilities. Linear movement, turning movement, lateral movement, rotating and rolling movement are achieved based on an inspired control model to produce rhythmic motion. In the end a conclusion and future work are given.
There is a clinical need for HIV protease inhibitors that can evade resistance mutations. One possible approach to designing such inhibitors relies upon the crystallographic observation that the substrates of HIV prot...
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There is a clinical need for HIV protease inhibitors that can evade resistance mutations. One possible approach to designing such inhibitors relies upon the crystallographic observation that the substrates of HIV protease occupy a rather constant region within the binding site. In particular, it has been hypothesized that inhibitors which lie within this region will tend to resist clinically relevant mutations. The present study offers the first prospective evaluation of this hypothesis, via computational design of inhibitors predicted to conform to the substrate envelope, followed by synthesis and evaluation against wild-type and mutant proteases, as well as structural studies of complexes of the designed inhibitors with HIV protease. The results support the utility of the substrate envelope hypothesis as a guide to the design of robust protease inhibitors.
With myriad information being generated from high-throughput experiments such as microarrays and sequencing technologies, an ever-increasing amount of data is being recorded and analyzed with the help of hierarchical ...
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ISBN:
(纸本)9780615153148
With myriad information being generated from high-throughput experiments such as microarrays and sequencing technologies, an ever-increasing amount of data is being recorded and analyzed with the help of hierarchical ontologies, such as the Gene Ontology (GO). We have developed a novel framework-based on the well established foundations of information theory - that allows for the evaluation of new types of hypotheses. The framework, encapsulated in Open Biomedical Ontology-Based Exploration and Search (OBOES), has already been applied in the investigation of different kinds of questions. The resulting framework enables the new field of information theoretic ontology-based analysis. We have applied this framework to create methods to re-engineer ontologies, explore fundamental questions on the evolution of biological complexity, determine optimal ontology terms for bioinformatics analysis, and quantify the usefulness of biofluids as proxies for tissues/diseases. In each case, we found that our methods provide novel, significant findings. An open source Java implementation of OBOES is available at: http://***. net.
In vivo neuroimaging methods permit longitudinal quantitative examination of the dynamic course of neurodegenerative conditions in humans and animal models and enable assessment of therapeutic efforts in mitigating di...
To overcome the overshoot and oscillation in the normal Bang-Bang controller applied in the pneumatic driving glass-wall cleaning robot, this paper presents a F&A compensating variable Bang-Bang control algorithm ...
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To overcome the overshoot and oscillation in the normal Bang-Bang controller applied in the pneumatic driving glass-wall cleaning robot, this paper presents a F&A compensating variable Bang-Bang control algorithm for the pneumatic position servo. Besides a new cylinder driving plan is designed, the control algorithm is also improved by adding a fiction force compensating item in the chamber force evaluation equation. To adjust the controlling parameters dynamically, certain increasing functions, such as step function, linear function and arc-tangent function, are used to define the piston's expectative acceleration along with the reduction of the piston's position error. To testify the feasibility of the control algorithms with the above three expectative acceleration setting functions respectively, a pneumatic glass-wall cleaning robot "Sky Cleaner 4" is used as a testing platform to implement a series of on-load position servo experiments. And the different results of them are compared.
Minimally invasive surgery (MIS) has become very common in recent years, thanks to the many advantages it provides for patients. Since it is difficult for surgeons to learn and master this technique, several training ...
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Minimally invasive surgery (MIS) has become very common in recent years, thanks to the many advantages it provides for patients. Since it is difficult for surgeons to learn and master this technique, several training methods and metrics have been proposed, both to improve the surgeon's abilities and also to assess his/her skills. This paper presents the use of the WB-1R (Waseda bioinstrumentation system no.1 refined), which was developed at Waseda University, Tokyo, to investigate and analyze a surgeon's movements and performance. Specifically, the system can measure the movements of the head, the arms, and the hands, as well as several physiological parameters. In this paper we present our experiment to evaluate a surgeon's ability to handle surgical instruments and his/her depth perception using a laparoscopic view. Our preliminary analysis of a subset of the acquired data (i.e. comfort of the subjects; the amount of time it took o complete each exercise; and respiration) clearly shows that the expert surgeon and the group of medical students perform very differently. Therefore, WB-1R (or, better, a newer version tailored specifically for use in the operating room) could provide important additional information to help assess the experience and performance of surgeons, thus leading to the development of a global performance index for surgeons during MIS. These analyses and modeling, moreover, are an important step towards the automatization and the robotic assistance of the surgical gesture.
Findings from several years of participant feedback about the NSF sponsored GK-12 Sensors! program at the University of Maine are described. The program places graduate Fellows in local K-12 classrooms, with the goal ...
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Findings from several years of participant feedback about the NSF sponsored GK-12 Sensors! program at the University of Maine are described. The program places graduate Fellows in local K-12 classrooms, with the goal of encouraging students to consider science, technology, engineering, and mathematics professions. Three broad themes are discussed: communication, preparation, and "fit." These factors determine the success of GK-12 Fellow placements, as shown by student and teacher evaluations, Fellow satisfaction, and classroom evaluations. Successful placements strengthen program implementation and status in participating schools while marginal placements can negatively affect both teachers and students and erode support for the GK-12 initiative.
Substantial research has been devoted to the modelling of the small-world phenomenon that arises in nature as well as human society. Earlier work has focused on the static properties of various small-world models. To ...
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Substantial research has been devoted to the modelling of the small-world phenomenon that arises in nature as well as human society. Earlier work has focused on the static properties of various small-world models. To examine the routing aspects, Kleinberg proposes a model based on a d-dimensional toroidal lattice with long-range links chosen at random according to the d-harmonic distribution. Kleinberg shows that, by using only local information, the greedy routing algorithm performs in O（lg^2 n） expected number of hops. We extend Kleinberg＇s small-world model by allowing each node x to have two more random links to nodes chosen uniformly and randomly within （lg n）2/d Manhattan distance from x. Based on this extended model, we then propose an oblivious algorithm that can route messages between any two nodes in O（lg n） expected number of hops. Our routing algorithm keeps only O（（lgn）β＋1） bits of information on each node, where 1 〈 β 〈 2, thus being scalable w.r.t, the network size. To our knowledge, our result is the first to achieve the optimal routing complexity while still keeping a poly-logarithmic number of bits of information stored on each node in the small-world networks.
A description of the so called "particles with coupled oscillator dynamics" (PCOD) is presented which is used to model, analyze and synthesize collective motion. An oscillator model with spatial dynamics is ...
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A description of the so called "particles with coupled oscillator dynamics" (PCOD) is presented which is used to model, analyze and synthesize collective motion. An oscillator model with spatial dynamics is presented to help describe how to design steering control laws while it is being used to study biological collectives. Lastly, both engineering and biological analysis were described.
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