Miura-Base Rigid Origami: Parametrizations of Curved-Crease Geometries

2014 ◽  
Vol 136 (12) ◽  
Author(s):  
Joseph M. Gattas ◽  
Zhong You
Keyword(s):  
Mechanical Performance ◽  
New Method ◽  
Additional Parameter ◽  
Matlab Toolbox ◽  
Subsequent Work ◽  
Folding Process ◽  
Two Stages

Curved-crease (CC) origami differs from prismatic, or straight-crease origami, in that the folded surface of the pattern is bent during the folding process. Limited studies on the mechanical performance of such geometries have been conducted, in part because of the difficulty in parametrizing and modeling the pattern geometry. This paper presents a new method for generating and parametrizing rigid-foldable, CC geometries from Miura-derivative prismatic base patterns. The two stages of the method, the ellipse creation stage and rigid subdivision stage, are first demonstrated on a Miura-base pattern to generate a CC Miura pattern. It is shown that a single additional parameter to that required for the straight-crease pattern is sufficient to completely define the CC variant. The process is then applied to tapered Miura, Arc, Arc-Miura, and piecewise patterns to generate CC variants of each. All parametrizations are validated by comparison with physical prototypes and compiled into a matlab Toolbox for subsequent work.

scholarly journals Characterizing Highly Benefited Patients in Randomized Clinical Trials

2017 ◽  
Vol 13 (1) ◽  
Author(s):  
Vivek Charu ◽  
Paul B. Rosenberg ◽  
Lon S. Schneider ◽  
Lea T. Drye ◽  
Lisa Rein ◽  
...  
Keyword(s):  
Randomized Clinical Trials ◽  
Controlled Trial ◽  
New Method ◽  
Usual Model ◽  
Randomized Controlled ◽  
Working Model ◽  
Large Numbers ◽  
High Benefit ◽  
Two Stages

AbstractPhysicians and patients may choose a certain treatment only if it is predicted to have a large effect for the profile of that patient. We consider randomized controlled trials in which the clinical goal is to identify as many patients as possible that can highly benefit from the treatment. This is challenging with large numbers of covariate profiles, first, because the theoretical, exact method is not feasible, and, second, because usual model-based methods typically give incorrect results. Better, more recent methods use a two-stage approach, where a first stage estimates a working model to produce a scalar predictor of the treatment effect for each covariate profile; and a second stage estimates empirically a high-benefit group based on the first-stage predictor. The problem with these methods is that each of the two stages is usually agnostic about the role of the other one in addressing the clinical goal. We propose a method that characterizes highly benefited patients by linking model estimation directly to the particular clinical goal. It is shown that the new method has the following two key properties in comparison with existing approaches: first, the meaning of the solution with regard to the clinical goal is the same, and second, the value of the solution is the best that can be achieved when using the working model as a predictor, even if that model is incorrect. In the Citalopram for Agitation in Alzheimer’s Disease (CitAD) randomized controlled trial, the new method identifies substantially larger groups of highly benefited patients, many of whom are missed by the standard method.

A Trial of Detecting Impending Access-graft Failure by Simplified Weekly Flow Monitoring

2005 ◽  
Vol 28 (3) ◽  
pp. 237-243 ◽  
Author(s):  
D. Vilkomerson ◽  
T. Chilipka ◽  
H. Rafi ◽  
P. Homel ◽  
G. Ghadari ◽  
...  
Keyword(s):  
Graft Failure ◽  
Controlled Trial ◽  
Effective Means ◽  
New Method ◽  
Control Group ◽  
Flow Monitoring ◽  
Monitoring Procedure ◽  
Two Stages ◽  
Induced Changes ◽  
Access Graft

Access graft failure is a major problem in hemodialysis. Monitoring the flow through the access so that impending failure can be detected and prevented seems reasonable, but recent clinical trials have failed to show any benefit of such monitoring. Described here are plans for a clinical trial of a new flow monitoring procedure that measures access flow weekly instead of monthly and, being performed before dialysis, avoids the dialysis-induced changes in graft flow that may have affected earlier trials. The planned trial is to be carried out in two stages, the first to establish the sensitivity and specificity of the new method, and the second (if the results of the first stage warrant it) a controlled trial comparing access-costs and hospitalization days between a monitored group and a matched standard care control group. It is hoped that this trial of the new method will establish it as an effective means of extending access-graft life.

FBG Sensor Application for GFRP Soil Nailing Pull-Out Test

2013 ◽  
Vol 477-478 ◽  
pp. 539-542 ◽  
Author(s):  
Qing Ping Jin ◽  
Zu Jia Zheng ◽  
Bin Qiang Dou ◽  
Xue Wen Lei
Keyword(s):  
Precise Measurement ◽  
Mechanical Performance ◽  
Difficult Problem ◽  
Soil Nailing ◽  
Pull Out ◽  
Sensing Technology ◽  
Pulling Force ◽  
Two Stages ◽  
Bragg Grating Sensor ◽  
Force Data

The mechanical performance of GFRP soil nailing in the supporting structure is an important and difficult problem. By implanting the fiber bragg grating sensor (FBG) into GFRP soil nailing, pull-out tests were done on filed,and stress rules of soil nailing bar were determined.The more reasonable and effective force data of soil nailings were also gathered through FBG senor.Test results show that the tension of soil nailing gradually adds with external pulling force, the variation of tension is divided into two stages, the total pulling force is within 50kN, growing linearly with about 2.5% rate ,after that, its growth rate is approximately 50% to 60%. After the force exceed a certain value, the load is transmitted backward.FBG sensing technology overcomes the failure problem of traditional strain sensor,is a precise measurement method.

scholarly journals Low Density Wood Particleboards Bonded with Starch Foam—Study of Production Process Conditions

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1975 ◽  
Author(s):  
Sandra Monteiro ◽  
Jorge Martins ◽  
Fernão D. Magalhães ◽  
Luísa Carvalho
Keyword(s):  
Mechanical Performance ◽  
Hold Time ◽  
Operating Conditions ◽  
Process Conditions ◽  
Low Density ◽  
Thickness Swelling ◽  
Hot Plate ◽  
Pressing Time ◽  
Two Stages ◽  
Platen Temperature

It has been shown that wood particleboards bonded with sour cassava starch can display low density combined with good physico-mechanical performance, thanks to starch being able to produce a strong foam that fills the interparticular space. Here we optimize the pressing conditions for the production of these panels. The procedure involved hot-plate pressing in two stages: (1) lowering the top platen to a specified thickness for a duration designated as pressing time, followed by (2) raising the top platen to allow panel expansion for a duration designated as hold time. The parameters studied were the pressing time (10 to 150 s), the hold time (290 to 890 s), and the top platen temperature (80 to 190 °C). The hold time and pressing time showed to be crucial parameters. The best operating conditions corresponded to 600 s of press cycle time, comprising 60 s of pressing time and 540 s of hold time. The top platen temperature used was 190 °C. The particleboards produced had a density of 405 kg·m−3, an internal bond strength of 0.44 N·mm−2, and a thickness swelling of 13.2%. This can be considered as very good performance, taking into account the panels’ low density.

The variation of comonomers feeding profile to design the distribution of chains composition for the optimization of the mechanical properties in copolymer systems

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Alvaro H. Arnez-Prado ◽  
Luis J. González-Ortiz ◽  
Francisco J. Aranda-García ◽  
Carlos F. Jasso-Gastinel
Keyword(s):  
Mechanical Performance ◽  
Loss Modulus ◽  
Polymeric Materials ◽  
Composition Distribution ◽  
Molecular Weights ◽  
Feeding Profile ◽  
Different Types ◽  
Izod Impact ◽  
Two Stages ◽  
Modulus Curve

AbstractSemicontinuous seeded emulsion copolymerizations, using 5 different types of feeding profiles of comonomers (styrene/butyl acrylate, S/BA) were carried out, to vary in a gradual manner the composition of the copolymer chains formed throughout the reactions (gradient composition copolymer, GCC). For comparison, equivalent core-shell type polymeric materials were synthesized in two stages (TS). In all reactions, the S/BA global mass ratio was: 70/30. To estimate the weight composition distribution (WCD) of the copolymer chains, the cumulative styrene content in the polymer mass was followed throughout the reaction (1H-NMR). Average molecular weights were determined using SEC. The differences in mechanical performance were established, carrying out a mechanodynamic (DMA), and mechanostatic characterization (stress-strain at several temperatures and, Izod testing). The area under the loss modulus curve (LA) was correlated with Izod impact strength, showing the damping superiority of the GCCs over the T-S material. At all tested temperatures (between 25 and 70 °C), the GCC materials exhibited yielding and plastic deformation, while the T-S material presented brittle fracture in that temperature interval. The WCDs were used to elucidate the differences in mechanical behaviour among GCC materials. The feeding profile variation in combination with the WCD analysis represents a novel methodology to produce tailor made copolymers.

Frequency Offset Estimation in Cell Search for TD-SCDMA UE

2012 ◽  
Vol 195-196 ◽  
pp. 254-258
Author(s):  
Ren Ming Peng ◽  
Zheng Tong Hao ◽  
Yang Mei
Keyword(s):  
Frequency Offset ◽  
New Method ◽  
Frame Synchronization ◽  
Frequency Offset Estimation ◽  
Cell Search ◽  
Sample Bias ◽  
System Requirements ◽  
Simulation Results ◽  
Two Stages

This paper describes a new method to implement frequency offset estimation (FOE) in cell search of the TD-SCDMA system. The received SYNC-DL data is used to calculate frequency offset (FO) before the scrambling code and the Midamble ID is identified. The received Midamble data can be used to calculate FO before Multi-frame synchronization. The FOE with two stages can be used in the same 64chip calculation structure and the hardware resources can be conserved. The simulation results show that the method can control the residual FO within 0.05PPM by smoothing of sub-frame or IIR filtering, which meets the TD-SCDMA system requirements for residual frequency, even though a certain sample bias exist.

Improvement of Stem Images by Means of Elimination of Influence of Statistical Fluctuation in Incident Electrons

1990 ◽  
Vol 48 (1) ◽  
pp. 184-185
Author(s):  
Hibino Michio ◽  
Takahiro Suzuki ◽  
Takaaki Hanai ◽  
Susumu Maruse
Keyword(s):  
Standard Deviation ◽  
Poisson Distribution ◽  
New Method ◽  
Statistical Fluctuation ◽  
Limit Set ◽  
Resolution Limit ◽  
Two Stages ◽  
Polynomial Distribution ◽  
Statistical Noise

The noise, due to statistical fluctuation of signal electrons, determines the ultimate resolution limit of imaging and analysis. The signal electrons (N) for each pixel are formed through two stages of statistical processes; Poisson distribution for the number of incident electrons (No) and polynomial distribution for forming signal electrons. The signal electrons therefore obey the Poisson distribution of average nOp (no:average of incident electrons, p:probability of forming signal electrons) and of standard deviation . In order to improve the resolution limit set by the statistical noise of signal electrons, a new method of normalization is proposed for STEM.In STEM imaging of thin specimens, the total transmitted electrons correspond to the incident electrons. It is therefore possible to know the incident electrons by summing up all the transmitted electrons and to normalize the signal electrons by incident electrons, for eliminating the influence of fluctuations of incident electrons. The average E and the standard deviation σ of normalized signal electrons are expressed by p and , respectively, for no> > 1 , indicating that E/σ value is improved by a factor of .

Funicular Polyhedra

1963 ◽  
Vol 30 (2) ◽  
pp. 219-224
Author(s):  
L. W. McKeehan
Keyword(s):  
Three Dimensional ◽  
Absolute Magnitude ◽  
New Method ◽  
Numerical Examples ◽  
Two Stages

The funicular polyhedron, the three-dimensional figure bounded by the links of a net supported at some of its knots (nodes), is treated theoretically by a new method in two stages. A geometrically allowable figure, with assumed coordinates of all supported nodes and of some others, is first computed consistently with the postulate that all the links are inextensible. The necessary vertical supporting forces at all nodes and horizontal forces at the supported nodes first specified, are then computed consistently with the postulate that the links are rigid and that their weights are supported equally at both ends without friction. Here additional vertical forces at nodes may be assumed at pleasure to simulate net-supported loads. Finally, vertical forces at nodes not meant to be supported are reduced in absolute magnitude, eventually to negligible values, by repeated small changes in their coordinates as assumed or computed in the first stage. There is some discussion of simple net types, and numerical examples of symmetrical funicular polyhedra of relatively few meshes are worked out precisely.

A New Method for Studying the Damage in Concrete Subjected Single Face Salt Freezing Cycle

2016 ◽  
Vol 680 ◽  
pp. 56-59 ◽  
Author(s):  
Wei Hong Li ◽  
Yi Han Wang ◽  
Yi Wang Bao ◽  
Zong Ming Yang
Keyword(s):  
Mechanical Performance ◽  
Test Body ◽  
New Method ◽  
Concrete Material ◽  
Damage Layer ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Concrete Damage ◽  
Damage Process ◽  
Freezing Cycle

Aiming at the shortcomings of traditional research method of materials mechanics performance of concrete, this paper presents a new method to test the mechanical properties of concrete material layer body--the relative method. It focuses on the use of relative principle, testing dynamic elastic modulus of concrete damage layer subjected to single salt freezing cyclic, and draw a gradient damage curve of concrete, and then study the damage process of the concrete under the effect of salt solution and the freeze-thaw cycle synergetic factors. The method provides a new way to test body layer mechanical performance of concrete material which the traditional methods can not be directly solved.

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