An Investigation of a Quality Index for the Stability of In-Parallel Planar Platform Devices

ROMANSY 11 ◽  
1997 ◽  
pp. 27-35 ◽  
Author(s):  
J. Lee ◽  
J. Duffy ◽  
M. Keler
Keyword(s):  
Quality Index ◽  
The Stability

The Optimum Quality Index for the Stability of In-Parallel Planar Platform Devices

1999 ◽  
Vol 121 (1) ◽  
pp. 15-20 ◽  
Author(s):  
J. Lee ◽  
J. Duffy ◽  
M. Keler
Keyword(s):  
Optimal Design ◽  
Equilateral Triangle ◽  
Quality Index ◽  
Optimal Shape ◽  
Geometrical Meaning ◽  
Moving Platforms ◽  
Maximum Value ◽  
Dimensionless Ratio ◽  
Parallel Platform ◽  
The Stability

The paper investigates primarily the geometrical meaning of the determinant of the Jacobian (det j) of the three connector lines of a planar in-parallel platform device using reciprocity. A remarkably simple result is deduced: The maximum value of det j namely, det jm is simply one-half of the sum of the lengths of the sides of the moving triangular platform. Further, this result is shown to be independent of the location of the fixed pivots in the base. A dimensionless ratio λ = |det j|/det jm is defined as the quality index (0 ≤ λ ≤ 1) and it is proposed here to use it to measure “closeness” to a singularity. An example which determines the optimal design by comparing different shaped moving platforms having the same det jm is given and demonstrates that the optimal shape is in fact an equilateral triangle

scholarly journals INFLUENCE OF THE AVERAGE WEIGHTED ESTIMATION TYPE ON THE DEPENDENCE OF THE COMPLEX QUALITY INDEX ON THE PARAMETERS OF OBJECT

2017 ◽  
Vol 8 (4) ◽  
pp. 398-407 ◽  
Author(s):  
A. M. Dolzhanskiy ◽  
O. A. Bondarenko ◽  
Ye. A. Petlyovaniy
Keyword(s):  
Quality Indicators ◽  
Quality Index ◽  
Informed Choice ◽  
Experiment Planning ◽  
Weighted Estimate ◽  
Arithmetic Average ◽  
Weighted Estimates ◽  
Control Factors ◽  
Calculation Results ◽  
The Stability

Objects quality is usually assessed by a complex indicator. It includes single quality indicators with their significance factors. The convolution of the corresponding dependencies represents average weighted quantities: arithmetic, geometric, harmonic, quadratic, etc. At the same time, the influence of the convolution type on the level of the complex quality index, the stability of the calculation results and, the reliability of the quality comparison among a number of similar objects is unknown in advance. Therefore, the aim of the study was to assess the influence of the average weighted type on the level and stability of the calculating results of the complex quality index in different objects compressing.For typical private objects compared the values of the complex quality index calculated according to the formulas of various average weighted estimates. Significance of the corresponding unit quality indicators, incompleteness of the object description and control factors influence on the object took into account.The results of the research were got using the method of virtual experiment planning. They showed that the influencing parameters changes, the calculated levels and stability of the complex quality index essentially depend on the type of convolution. It was shown that under the priori uncertainty of the necessary convolution for the best representative choosing of the corresponding class of objects, the arithmetic average weighted estimate is the best for using.The obtained data can serve as a basis for an informed choice of the type of average weighted in the quality assessment of various objects and decision-making on rational levels of controlled factors.

The Optimum Quality Index for the Stability of In-Parallel Planar Platform Devices

1996 ◽  
Author(s):  
Jaehoon Lee ◽  
Joseph Duffy ◽  
Max Keler
Keyword(s):  
Optimal Design ◽  
Equilateral Triangle ◽  
Quality Index ◽  
Optimal Shape ◽  
Geometrical Meaning ◽  
Moving Platforms ◽  
Maximum Value ◽  
Dimensionless Ratio ◽  
Parallel Platform ◽  
The Stability

Abstract The paper investigates primarily the geometrical meaning of the determinant of the Jacobian (det j) of the three connector lines of a planar in-parallel platform device using reciprocity. A remarkably simple result is deduced : The maximum value of det j namely, det jm is simply one-half of the sum of the lengths of the sides of the moving triangular platform. Further, this result is shown to be independent of the location of the fixed pivots in the base. A dimensionless ratio λ = |det j| / det jm is defined as the quality index (0 ≤ λ ≤ 1) and it is proposed here to use it to measure “closeness” to a singularity. An example which determines the optimal design by comparing different shaped moving platforms having the same det jm is given and demonstrates that the optimal shape is in fact an equilateral triangle.

scholarly journals Impact of Hydrological Study to Water Quality Status in Kuantan River, Pahang, Malaysia

2018 ◽  
Vol 7 (3.14) ◽  
pp. 35 ◽  
Author(s):  
Frankie Marcus Ata ◽  
Mohd Khairul Amri Kamarudin ◽  
Nadzifah Yaakub ◽  
Noorjima Abd. Wahab ◽  
Mohd Ekhwan Toriman ◽  
...  
Keyword(s):  
Water Quality ◽  
Quality Index ◽  
Quality Standard ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Band Erosion ◽  
Bed Sediments ◽  
Resources Management ◽  
Water Quality Status ◽  
The Stability

Water is a vital for all aspects of human and ecosystem survival. The evaluations of water quality parameters and hydrological status are necessary to enhance the performance of an assessment operation and develop better water resources management and plan. There are three sampling stations were selected along the Kuantan River. Seven water quality parameters were measured and Malaysian Department of Environment Water Quality Index (DOE-WQI) was calculated and classified based on the National Water Quality Standard, Malaysia (INWQS). The water balance status applied to determine the stability of inflows and outflows into and from the basin. As a result, all water quality parameters (DO, COD, BOD, TSS, NH3-N and pH) which categorized under the ranged of class II until class IV respectively. Kuantan River located in Pahang state, Malaysia which is significantly degrading due to human activities as well as urbanization in and within the area. Overall, the result showed that the estimated average sediment that flows out of Kuantan Rivers is 108.88tonnes/day (24 February 2017) and 44.917 tonnes/day (30 April 2017). The contributors of sedimentation problems in Kuantan River are from unsustainable land use such as urbanization and industrialization which trapping the bed sediments and river band erosion.  

scholarly journals STABILITAS HASIL DAN ADAPTABILITAS KULTIVAR TEMBAKAU MAGETAN MENGGUNAKAN METODE EBERHART RUSSELL

2020 ◽  
Vol 8 (2) ◽  
pp. 337
Author(s):  
Ruly Hamida ◽  
Mala Murianingrum ◽  
Djumali Djumali
Keyword(s):  
Dynamic Stability ◽  
Quality Index ◽  
Block Design ◽  
Yield Stability ◽  
Cigarette Industry ◽  
Research Material ◽  
Randomized Block Design ◽  
Stable Yield ◽  
The Stability

Magetan tobacco is one type of tobacco that has an important role in the kretek cigarette industry in Indonesia. Some tobacco varieties have been widely cultivated in the Magetan Regency, but the level of plant heterogeneity is quite high. The purpose of this study was to assess the yield, stability and adaptability of varieties that developed in Magetan Regency. The research material consists of 7 tobacco varieties, namely Rejeb 1, Rejeb 2, Rejeb 3, Rejeb 4, Rejeb 5, Rejeb 6, and Rejeb 7. Each variety was planted in a 12 m x 4.50 m plot with a spacing of 60 cm x 90 cm (100 plants / plot). This study used a randomized block design with three replications. The stability of the results was analyzed by the Eberhart and Russell methods. The results showed that Rejeb 4 cultivar gave the highest and stable yield of 598.89 kg / ha, higher than all cultivars tested. This is in line with the quality index and plant index values, where the Rejeb 4 variety gave the highest value in five test locations (63.65 and 38.34). Subsequently followed by cultivars Rejeb 3, Rejeb 2, and Rejeb 1 which have dynamic stability and adaptability values.

Open discussion

1982 ◽  
Vol 99 ◽  
pp. 605-613
Author(s):  
P. S. Conti
Keyword(s):  
Buenos Aires ◽  
Large Mass ◽  
List Type ◽  
Common Phenomenon ◽  
Open Discussion ◽  
The Stability ◽  
Ring Nebulae

Conti: One of the main conclusions of the Wolf-Rayet symposium in Buenos Aires was that Wolf-Rayet stars are evolutionary products of massive objects. Some questions:–Do hot helium-rich stars, that are not Wolf-Rayet stars, exist?–What about the stability of helium rich stars of large mass? We know a helium rich star of ∼40 MO. Has the stability something to do with the wind?–Ring nebulae and bubbles : this seems to be a much more common phenomenon than we thought of some years age.–What is the origin of the subtypes? This is important to find a possible matching of scenarios to subtypes.

Symmetric Multistep Methods Revisited: II. Numerical Experiments

1999 ◽  
Vol 173 ◽  
pp. 309-314 ◽  
Author(s):  
T. Fukushima
Keyword(s):  
Multistep Methods ◽  
Computational Time ◽  
Integration Time ◽  
Implicit Methods ◽  
Symmetric Methods ◽  
Celestial Bodies ◽  
The Stability ◽  
Predictor Corrector ◽  
Symmetric Multistep Methods ◽  
Integration Errors

AbstractBy using the stability condition and general formulas developed by Fukushima (1998 = Paper I) we discovered that, just as in the case of the explicit symmetric multistep methods (Quinlan and Tremaine, 1990), when integrating orbital motions of celestial bodies, the implicit symmetric multistep methods used in the predictor-corrector manner lead to integration errors in position which grow linearly with the integration time if the stepsizes adopted are sufficiently small and if the number of corrections is sufficiently large, say two or three. We confirmed also that the symmetric methods (explicit or implicit) would produce the stepsize-dependent instabilities/resonances, which was discovered by A. Toomre in 1991 and confirmed by G.D. Quinlan for some high order explicit methods. Although the implicit methods require twice or more computational time for the same stepsize than the explicit symmetric ones do, they seem to be preferable since they reduce these undesirable features significantly.

Uniformity of Magnification from Different Electron Microscopes

1967 ◽  
Vol 25 ◽  
pp. 32-33
Author(s):  
Godfrey C. Hoskins ◽  
V. Williams ◽  
V. Allison
Keyword(s):  
Diffraction Grating ◽  
The Other ◽  
Carbon Replica ◽  
Electron Microscopes ◽  
The Stability

The method demonstrated is an adaptation of a proven procedure for accurately determining the magnification of light photomicrographs. Because of the stability of modern electrical lenses, the method is shown to be directly applicable for providing precise reproducibility of magnification in various models of electron microscopes.A readily recognizable area of a carbon replica of a crossed-line diffraction grating is used as a standard. The same area of the standard was photographed in Phillips EM 200, Hitachi HU-11B2, and RCA EMU 3F electron microscopes at taps representative of the range of magnification of each. Negatives from one microscope were selected as guides and printed at convenient magnifications; then negatives from each of the other microscopes were projected to register with these prints. By deferring measurement to the print rather than comparing negatives, correspondence of magnification of the specimen in the three microscopes could be brought to within 2%.

Effect of Improved ThO2 Particle Dispersion in Nickel on High-Temperature Strength

1970 ◽  
Vol 28 ◽  
pp. 444-445
Author(s):  
E. R. Kimmel ◽  
H. L. Anthony ◽  
W. Scheithauer
Keyword(s):  
High Temperature ◽  
Metal Matrix ◽  
Oxide Particle ◽  
Oxide Phase ◽  
Dislocation Motion ◽  
Particle Dispersion ◽  
High Temperature Strength ◽  
Strengthening Effect ◽  
Oxide Particles ◽  
The Stability

The strengthening effect at high temperature produced by a dispersed oxide phase in a metal matrix is seemingly dependent on at least two major contributors: oxide particle size and spatial distribution, and stability of the worked microstructure. These two are strongly interrelated. The stability of the microstructure is produced by polygonization of the worked structure forming low angle cell boundaries which become anchored by the dispersed oxide particles. The effect of the particles on strength is therefore twofold, in that they stabilize the worked microstructure and also hinder dislocation motion during loading.

An Analysis of Dissociation of Molecules in a High Resolution Electron Microscope

1973 ◽  
Vol 31 ◽  
pp. 486-487
Author(s):  
Mihir Parikh
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Cross Sections ◽  
Resolving Power ◽  
Peak Intensity ◽  
Molecular Film ◽  
Resolution Electron ◽  
Dissociation Cross Section ◽  
High Resolution Electron Microscope ◽  
The Stability

It is well known that the resolution of bio-molecules in a high resolution electron microscope depends not just on the physical resolving power of the instrument, but also on the stability of these molecules under the electron beam. Experimentally, the damage to the bio-molecules is commo ly monitored by the decrease in the intensity of the diffraction pattern, or more quantitatively by the decrease in the peaks of an energy loss spectrum. In the latter case the exposure, EC, to decrease the peak intensity from IO to I’O can be related to the molecular dissociation cross-section, σD, by EC = ℓn(IO /I’O) /ℓD. Qu ntitative data on damage cross-sections are just being reported, However, the microscopist needs to know the explicit dependence of damage on: (1) the molecular properties, (2) the density and characteristics of the molecular film and that of the support film, if any, (3) the temperature of the molecular film and (4) certain characteristics of the electron microscope used

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