scholarly journals Automated Axis Alignment for a Nanomanipulator inside SEM and Its Error Optimization

Scanning ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Chao Zhou ◽  
Lu Deng ◽  
Long Cheng ◽  
Zhiqiang Cao ◽  
Shuo Wang ◽  
...  
Keyword(s):  
Average Method ◽  
Closed Loop ◽  
Alignment Method ◽  
Visual Servo ◽  
End Effector ◽  
Axis Alignment ◽  
Deposition Effect ◽  
Relationship Of ◽  
The Relationship ◽  
Error Optimization

In the motion of probing nanostructures, repeating position and movement is frequently happing and tolerance for position error is stringent. The consistency between the axis of manipulators and image is very significant since the visual servo is the most important tool in the automated manipulation. This paper proposed an automated axis alignment method for a nanomanipulator inside the SEM by recognizing the position of a closed-loop controlling the end-effector, which can characterize the relationship of these two axes, and then the rotation matrix can be calculated accordingly. The error of this method and its transfer function are also calculated to compare the iteration method and average method. The method in this paper can accelerate the process of axis alignment to avoid the electron beam induced deposition effect on the end tips. Experiment demonstration shows that it can achieve a 0.1-degree precision in 90 seconds.

scholarly journals Automated Kinematic Analysis of Closed-Loop Planar Link Mechanisms

Machines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 41
Author(s):  
Tatsuya Yamamoto ◽  
Nobuyuki Iwatsuki ◽  
Ikuma Ikeda
Keyword(s):  
Kinematic Analysis ◽  
Closed Loop ◽  
Analysis Procedure ◽  
Linkage Mechanism ◽  
A Algorithm ◽  
Analysis Process ◽  
Type Transformation ◽  
Extraction Algorithm ◽  
Relationship Of ◽  
The Relationship

The systematic kinematic analysis method for planar link mechanisms based on their unique procedures can clearly show the analysis process. The analysis procedure is expressed by a combination of many kinds of conversion functions proposed as the minimum calculation units for analyzing a part of the mechanism. When it is desired to perform this systematic kinematics analysis for a specific linkage mechanism, expert researchers can accomplish the analysis by searching for the procedure by themselves, however, it is difficult for non-expert users to find the procedure. This paper proposes the automatic procedure extraction algorithm for the systematic kinematic analysis of closed-loop planar link mechanisms. By limiting the types of conversion functions to only geometric calculations that are related to the two-link chain, the analysis procedure can be represented by only one type transformation function, and the procedure extraction algorithm can be described as a algorithm searching computable 2-link chain. The configuration of mechanism is described as the “LJ-matrix”, which shows the relationship of connections between links with pairs. The algorithm consists of four sub-processes, namely, “LJ-matrix generator”, “Solver process”, “Add-link process”, and “Over-constraint resolver”. Inputting the sketch of the mechanism into the proposed algorithm, it automatically extracts unique analysis procedure and generate a kinematic analysis program as a MATLAB code based on it. Several mechanisms are analyzed as examples to show the usefulness of the proposed method.

On the elimination of branching in the synthesis of spatial single-loop mechanisms with lower pairs

Robotica ◽  
1988 ◽  
Vol 6 (2) ◽  
pp. 149-154
Author(s):  
George N. Sandor ◽  
Yongxian Xu ◽  
Tzu-Chen Weng
Keyword(s):  
Closed Loop ◽  
End Effector ◽  
Single Loop ◽  
Spatial Mechanism ◽  
The Relationship ◽  
Motion Generator ◽  
Loop Motion

SUMMARYA single-loop spatial mechanism kinematically becomes an open robot, if we separate the grounded joint of the input link which may then be considered as the end effector of the robot. Any position of the end-effector within the workspace of such an open robot can be reached via a number of different configurations of the links. These configurations are called “branches” of the open robot for that particular position of the end effector.If the open robot is now stretched to a limiting position by a force exerted on the end effector, all the possible branches of the mechanism approach each other. When they become coincident, they form the “limiting configuration”. Any two related branches are at opposite sides of the limiting configuration. From the relationship between the links in th elimiting configuration and in related branches, conditions for aviodance of branching of the original closed-loop mechanism can be obtained. This is necessary in order to assure that a set of consistent relative displacements are specified for the open robot to move displacements are specified for the open robot to move toward the desired end-effector position without jumping from one branch to another. As for the closed-loop mechanism, open robot branching aviodance ensures that a desired sequence of positions of a particular floating link in the loop will be generated without changing the branch of the link configuration.In this paper, the above approach is applied to RSSR, RRSC, RRSRR, RRRRRRR and RPCRRR spatial closed-loop motion-generator mechanisms and the corresponding conditions for aviodance of branching in the synthesis of the mechanisms are derived.

scholarly journals The alignment of the axis of asymmetry in regenerating protoplasts of the moss, Ceratodon purpureus, is determined independently of axis polarity

Development ◽  
1996 ◽  
Vol 122 (1) ◽  
pp. 371-379 ◽  
Author(s):  
D.J. Cove ◽  
R.S. Quatrano ◽  
E. Hartmann
Keyword(s):  
White Light ◽  
Incident Light ◽  
Red Light ◽  
Opposite Polarity ◽  
Genetic Dissection ◽  
Axis Alignment ◽  
Directional Stimulus ◽  
Almost All ◽  
Relationship Of ◽  
The Relationship

Ceratodon protoplasts regenerate by polar outgrowth to form cell filaments. The kinetics of regeneration show that some cellular event has to be completed before regeneration can be initiated. The development of the regeneration axis is strongly influenced by light, with axis alignment and axis polarity being fixed independently. We define axis alignment as the relationship of the regeneration axis to the incident light, independent of polarity. Thus protoplasts regenerating directly towards, or directly away from the light source are defined as being similarly aligned but with opposite polarity. Protoplasts that regenerate in unidirectional red light form axes that are aligned parallel to the light direction, with about 70% being polarised towards the light and about 30% away. In unidirectional blue or white light, almost all protoplasts regenerate towards the light but axis alignment is determined less stringently. Re-orientation of protoplasts regenerating in unidirectional light shows that axis alignment is fixed between 8 and 9 hours before protoplasts regenerate and that axis polarity is fixed later. When protoplasts are removed from directional light to either non-directional light or to darkness, regeneration axes continue to be aligned by the earlier directional stimulus for at least 24 hours. Thus although axis alignment is fixed only about 8 hours before regeneration, in the absence of contradictory information about directionality in the light environment, protoplasts retain a memory of light direction for much longer. However, both reorientation and removal from a directional light field have profound effects on axis polarity; the pattern observed in undisturbed protoplasts being lost. To account for these observations, we propose that separate gradients are established independently to determine the alignment and polarity of the regeneration axis respectively. The alignment gradient is established rapidly and is steeper in red than in blue or white light, the polarity gradient is established slowly and is steeper in white or blue light than in red. These studies will now allow a genetic dissection of these processes in moss.

Relationship of Objective Score, Perceptual Trace, and Practice Method in Learning to Balance

1975 ◽  
Vol 40 (1) ◽  
pp. 331-337 ◽  
Author(s):  
Ronald Bole
Keyword(s):  
Closed Loop ◽  
Main Concern ◽  
Loop Theory ◽  
Mixed Support ◽  
Practice Method ◽  
The Difference ◽  
Relationship Of ◽  
The Relationship ◽  
Objective Score

The relationship of the perceptual trace to the objective score (raw score) under three practice conditions was the main concern of this study. Three groups of 14 Ss performed 35 trials on a stabilometer balancing task. Ss were asked to estimate how well they did after each trial. The difference between S's actual score and his guess was used as a measure of the perceptual trace. While performance and time estimations improved with practice, they correlated very low. The results were discussed in the context of Adams' closed-loop theory and gave mixed support for the theory.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Studies on Leukemogenic and Sarcomagenic Viruses

1970 ◽  
Vol 28 ◽  
pp. 156-157
Author(s):  
Leon Dmochowski
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Morphological Properties ◽  
Mode Of Development ◽  
Relationship Of ◽  
The Relationship

Electron microscopy has proved to be an invaluable discipline in studies on the relationship of viruses to the origin of leukemia, sarcoma, and other types of tumors in animals and man. The successful cell-free transmission of leukemia and sarcoma in mice, rats, hamsters, and cats, interpreted as due to a virus or viruses, was proved to be due to a virus on the basis of electron microscope studies. These studies demonstrated that all the types of neoplasia in animals of the species examined are produced by a virus of certain characteristic morphological properties similar, if not identical, in the mode of development in all types of neoplasia in animals, as shown in Fig. 1.

The relationship of IGE receptor topography to signaling activity in RBL-2H3 mast cells

1991 ◽  
Vol 49 ◽  
pp. 236-237
Author(s):  
J.R. Pfeiffer ◽  
J.C. Seagrave ◽  
C. Wofsy ◽  
J.M. Oliver
Keyword(s):  
Mast Cells ◽  
Protein A ◽  
Scattered Electron ◽  
Ige Receptor ◽  
Receptor Complexes ◽  
Ige Binding ◽  
Electron Imaging ◽  
Small Clusters ◽  
Relationship Of ◽  
The Relationship

In RBL-2H3 rat leukemic mast cells, crosslinking IgE-receptor complexes with anti-IgE antibody leads to degranulation. Receptor crosslinking also stimulates the redistribution of receptors on the cell surface, a process that can be observed by labeling the anti-IgE with 15 nm protein A-gold particles as described in Stump et al. (1989), followed by back-scattered electron imaging (BEI) in the scanning electron microscope. We report that anti-IgE binding stimulates the redistribution of IgE-receptor complexes at 37“C from a dispersed topography (singlets and doublets; S/D) to distributions dominated sequentially by short chains, small clusters and large aggregates of crosslinked receptors. These patterns can be observed (Figure 1), quantified (Figure 2) and analyzed statistically. Cells incubated with 1 μg/ml anti-IgE, a concentration that stimulates maximum net secretion, redistribute receptors as far as chains and small clusters during a 15 min incubation period. At 3 and 10 μg/ml anti-IgE, net secretion is reduced and the majority of receptors redistribute rapidly into clusters and large aggregates.

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