scholarly journals The optimal number of faces in cubical complexes

1971 ◽  
Vol 8 (3) ◽  
pp. 245-257 ◽  
Author(s):  
Bernt Lindström
Keyword(s):  
Optimal Number ◽  
Cubical Complexes ◽  
Number Of Faces

scholarly journals Optimal number of faces for fast self-folding kirigami

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
H. P. M. Melo ◽  
C. S. Dias ◽  
N. A. M. Araújo
Keyword(s):  
Optimal Number ◽  
Number Of Faces

scholarly journals ANALYSIS OF THE INFLUENCE OF THE FORM AND DIMENSIONS OF THE CROSS-SECTION OF CLEANLESS TAPERS ON THE PROCESS OF EXTRACTING THREADS

2020 ◽  
pp. 108-122
Author(s):  
Oleksіі Tokarchuk
Keyword(s):  
Cross Section ◽  
Practical Interest ◽  
Average Diameter ◽  
Extrusion Process ◽  
Optimal Number ◽  
Operational Characteristics ◽  
Number Of Faces ◽  
The Stability ◽  
Actual Geometry ◽  
Profile Change

The method of manufacturing internal threads with chipless taps, including mutual pumping of the tool and the workpiece, as in the manufacture of external thread profiles, so it cannot be entered into the knurling methods. Due to the specific features of the thread extrusion process, the study of the operational characteristics of rubber manufactured by chipless taps is of practical interest. The extrusion of threads occurs at a temperature not reaching the temperature of recrystallization of the metal of the workpiece, however, the physic mechanical properties of the surface layer of the metal of the threaded profile change. As a result of cold displacement of the threaded profile, the metal flows in the threaded contour. Extrusion of internal threads by chipless taps is a method of plastic deformation of a metal, in which a special tapping rod with a profile of the necessary thread is screwed into a workpiece opening, which has a diameter equal to approximately the average diameter of the thread. Under the action of torque, the tops of the turns of the tapered intake part of the tap penetrate the surface of the billet hole, the displaced metal moves in the radial direction, gradually increasing the height of the threaded profile. The actual geometry of the vertices of the tool cross-section contour has a significant effect on the thread extrusion process. Depending on the ratio of the contact planes of the tool and the workpiece, depending on the permissible amount of backing, the greatest torque is observed in hexagonal taps, and the smallest in trihedral taps. Depending on the accepted backing value, the ratio between the lengths and areas of the contacting sections, and accordingly, the ratio between the torques for taps with a different number of faces, also changes. It should be noted that in addition to the magnitude of the torque, the second parameter characterizing the process of extruding threads is the stability of the taps, which is not directly related to the magnitude of the torque, then the optimal number of faces is n = 3. If the optimal number of faces simultaneously satisfies two criteria (minimum torque and maximum tool life), then the optimal number of faces is determined experimentally in a specific case

Optimal Experimental Design With Nesting of Persons in Organizations

2013 ◽  
Vol 221 (3) ◽  
pp. 145-159 ◽  
Author(s):  
Gerard J. P. van Breukelen
Keyword(s):  
Repeated Measures ◽  
Optimal Number ◽  
Health Centers ◽  
Randomized Experiments ◽  
Optimal Sample ◽  
Treatment Conditions ◽  
Sampling Cost ◽  
Nested Designs ◽  
Simple Equations ◽  
Number Of Individuals

This paper introduces optimal design of randomized experiments where individuals are nested within organizations, such as schools, health centers, or companies. The focus is on nested designs with two levels (organization, individual) and two treatment conditions (treated, control), with treatment assignment to organizations, or to individuals within organizations. For each type of assignment, a multilevel model is first presented for the analysis of a quantitative dependent variable or outcome. Simple equations are then given for the optimal sample size per level (number of organizations, number of individuals) as a function of the sampling cost and outcome variance at each level, with realistic examples. Next, it is explained how the equations can be applied if the dependent variable is dichotomous, or if there are covariates in the model, or if the effects of two treatment factors are studied in a factorial nested design, or if the dependent variable is repeatedly measured. Designs with three levels of nesting and the optimal number of repeated measures are briefly discussed, and the paper ends with a short discussion of robust design.

AMOUNT AND STRUCTURE OF THE BIOLOGICAL FERTILITY OF SOYA, DEPENDING ON THE SYSTEM OF MAIN TILLAGE OF SOIL AND MEASURES TO OPTIMIZE NUTRITION MODE

2020 ◽  
Author(s):  
M. Novokhatskyi ◽  
◽  
V. Targonya ◽  
T. Babinets ◽  
O. Gorodetskyi ◽  
...  
Keyword(s):  
Field Experiments ◽  
Optimal Number ◽  
Soil Tillage ◽  
Forest Steppe ◽  
Biological Productivity ◽  
Tillage Systems ◽  
Application Rates ◽  
Tillage System ◽  
Biological Yield ◽  
The Impact

Aim. Assessment of the impact of the most common systems of basic tillage and biological methods of optimization of nutrition regimes on the realization of the potential of grain productivity of soybean in the Forest-Steppe of Ukraine. Methods. The research used general scientific (hypothesis, experiment, observation) and special (field experiment, morphological analysis) methods Results. The analysis of the results of field experiments shows that the conservation system of soil cultivation, which provided the formation of 27.6 c/ha of grain, is preferable by the level of biological yield of soybean. The use of other systems caused a decrease in the biological yield level: up to 26.4 c/ha for the use of the traditional system, up to 25.3 c/ha for the use of mulching and up to 23.0 c/ha for the use of the mini-till. With the use of Groundfix, the average biological yield of soybean grain increases to 25.6 c / ha for application rates of 5 l/ha, and to 28.2 c/ha for application rates of 10 l/ha when control variants (without the use of the specified preparation) an average of 22.6 c/ha of grain was formed with fluctuations in soil tillage systems from 21.0 (mini-bodies) to 25.8 c/ha (traditional).The application of Groundfix (10 l/ha) reduced the seed abortion rate from 11.0% (average without biofertilizer variants) to 8.0%, forming the optimal number of stem nodes with beans, increasing the attachment height of the lower beans and improving other indicators of biological productivity soybeans. Conclusions. It has been found that the use of the canning tillage system generates an average of 27.6 cent soybean grains, which is the highest indicator among the main tillage systems within the scheme of our research. The use of Groundfix caused a change in this indicator: if the variants with a conservative system of basic tillage without the use of biological preparation (control) were formed on average 24.1 c/ha, the use of Ground Licks caused the increase of biological productivity up to 29.4 c/ha, and at a dose of 10 l/ha biological yield was 32.2 c/ha. It was found that both the use of Groundfix and the basic tillage system influenced the elements of the yield structure: the density of the plants at the time of harvest depended more on the tillage system than on the use of Groundfix; the use of Groundfix and increasing its dose within the scheme of our studies positively reflected on the density of standing plants; the height of attachment of the lower beans and reduced the abortion of the seeds.

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