scholarly journals Randomly coloring constant degree graphs

2012 ◽  
Vol 43 (2) ◽  
pp. 181-200 ◽  
Author(s):  
Martin Dyer ◽  
Alan Frieze ◽  
Thomas P. Hayes ◽  
Eric Vigoda
Keyword(s):  
Constant Degree

Optimization of Operation Parameters for Direct Spring Loaded Pressure Relief Valve in a Pipeline System

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Hyunjun Kim ◽  
Sanghyun Kim ◽  
Youngman Kim ◽  
Jonghwan Kim
Keyword(s):  
Pressure Relief Valve ◽  
Pipeline System ◽  
Relief Valve ◽  
Pressure Relief ◽  
Computational Costs ◽  
Constant Degree ◽  
System A ◽  
Disk Mass ◽  
Analysis Scheme ◽  
Surge Control

A direct spring loaded pressure relief valve (DSLPRV) is an efficient hydraulic structure used to control a potential water hammer in pipeline systems. The optimization of a DSLPRV was explored to consider the instability issue of a valve disk and the surge control for a pipeline system. A surge analysis scheme, named the method of characteristics, was implemented into a multiple-objective genetic algorithm to determine the adjustable factors in the operation of the DSLPRV. The forward transient analysis and multi-objective optimization of adjustable factors, such as the spring constant, degree of precompression, and disk mass, showed substantial relaxation in the surge pressure and oscillation of valve disk in a hypothetical pipeline system. The results of the regression analysis of surge were compared with the optimization results to demonstrate the potential of the developed method to substantially reduce computational costs.

Standardized reaction times used to describe the mechanism of enzyme-induced gelation in whey protein systems

2000 ◽  
Vol 67 (3) ◽  
pp. 403-413 ◽  
Author(s):  
RICHARD IPSEN ◽  
JEANETTE OTTE ◽  
STIG B. LOMHOLT ◽  
KARSTEN B. QVIST
Keyword(s):  
Whey Protein ◽  
Reaction Times ◽  
Enzyme Concentration ◽  
Protein Isolate ◽  
Effect Of Temperature ◽  
Degree Of Hydrolysis ◽  
Thermally Induced ◽  
Constant Degree ◽  
Increasing Temperature ◽  
Rate Limiting

Whey protein isolate (WPI), either untreated or pretreated at 80 °C for 30 min, was incubated with a proteinase from Bacillus licheniformis until a gel was formed. Standardized reaction times, directly linked to the degree of hydrolysis, were obtained from plots of the relative amount of peptides released v. reaction time obtained under different conditions (enzyme concentration, temperature, pH, NaCl addition). This provided a connection between the gelation profile and the degree of hydrolysis. In the case of untreated WPI, gelation occurred at lower degrees of proteolysis when the enzyme concentration was decreased, demonstrating that a rate-limiting aggregation process occurred at the same time as the proteolysis in a manner similar to the renneting of milk. This was not the case for preheated WPI, when gelation was found to take place at a constant degree of proteolysis, independent of the enzyme concentration. In this case, the mechanism could be described by assuming the thermally induced aggregates present in this substrate had progressively more stabilizing peptide segments shaved off, resulting in increased attraction between individual aggregates that ultimately led to gelation. Results obtained at 40–60 °C supported this, as we found no effect of temperature on the degree of proteolysis at gelation for the untreated WPI, whereas the degree of proteolysis decreased with increasing temperature when heated WPI was hydrolysed. The effect of pH and NaCl addition on the process was to reduce repulsion between the aggregating species so that gelation was induced at a decreased degree of proteolysis.

Lower Bounds on OBDD Proofs with Several Orders

2021 ◽  
Vol 22 (4) ◽  
pp. 1-30
Author(s):  
Sam Buss ◽  
Dmitry Itsykson ◽  
Alexander Knop ◽  
Artur Riazanov ◽  
Dmitry Sokolov
Keyword(s):  
Lower Bound ◽  
Lower Bounds ◽  
Communication Complexity ◽  
Multiparty Communication ◽  
Constant Degree ◽  
Polynomial Size ◽  
Explicit Constant ◽  
Open Question ◽  
System 1 ◽  
Exponential Size

This article is motivated by seeking lower bounds on OBDD(∧, w, r) refutations, namely, OBDD refutations that allow weakening and arbitrary reorderings. We first work with 1 - NBP ∧ refutations based on read-once nondeterministic branching programs. These generalize OBDD(∧, r) refutations. There are polynomial size 1 - NBP(∧) refutations of the pigeonhole principle, hence 1-NBP(∧) is strictly stronger than OBDD}(∧, r). There are also formulas that have polynomial size tree-like resolution refutations but require exponential size 1-NBP(∧) refutations. As a corollary, OBDD}(∧, r) does not simulate tree-like resolution, answering a previously open question. The system 1-NBP(∧, ∃) uses projection inferences instead of weakening. 1-NBP(∧, ∃ k is the system restricted to projection on at most k distinct variables. We construct explicit constant degree graphs G n on n vertices and an ε > 0, such that 1-NBP(∧, ∃ ε n ) refutations of the Tseitin formula for G n require exponential size. Second, we study the proof system OBDD}(∧, w, r ℓ ), which allows ℓ different variable orders in a refutation. We prove an exponential lower bound on the complexity of tree-like OBDD(∧, w, r ℓ ) refutations for ℓ = ε log n , where n is the number of variables and ε > 0 is a constant. The lower bound is based on multiparty communication complexity.

The Torsional Properties of Normal and Sulfur-Enriched Wool Fibers

1969 ◽  
Vol 39 (3) ◽  
pp. 261-266 ◽  
Author(s):  
L. D. Armstrong ◽  
M. Feughelman
Keyword(s):  
Mechanical Properties ◽  
Sulfur Content ◽  
Distilled Water ◽  
Constant Degree ◽  
Wool Fibers ◽  
The Difference ◽  
Decreasing Ph ◽  
Low Sulfur Content ◽  
Low Sulfur ◽  
Torsional Properties

The mechanical properties in torsion of single wool fibers of biologically produced high- and low-sulfur content have been studied to determine the effects on torsional behavior. The modulus of rigidity and the torsional relaxation, i.e., the decay in torque with time at a constant degree of twist, were determined in fibers tested in glycerol (~0% RH), distilled water, and aqueous solutions of HCl at pH 0.8, 1.8, and 2.9. The sulfur content had no significant effect on the modulus of ridigidy or on the magnitude of the torsional relaxation of dry fibers. Again, for fibers tested in distilled water, no significant effect of sulfur content on the modulus of rigidity was observed, but the percent decay in torque was measurably affected. The decay in torque in 1 hr for fibers of normal wool amounted to 23% of the initial torque and that for fibers of sulfur-enriched wool amounted to 15%. This difference in torsional relaxation behavior of wet fibers of the two wools was not thought to be due to the difference in sulfur content but may partly be linked with the aspartic acid content of the two wools. The modulus of rigidity and the torsional relaxation of fibers in aqueous HCl decreased with decreasing pH to as little as one third of the values obtained in distilled water, presumably due to the breaking of salt links, the decrease being greater for the sulfur-enriched wools.

scholarly journals A note on distinct distances

2020 ◽  
Vol 29 (5) ◽  
pp. 650-663
Author(s):  
Orit E. Raz
Keyword(s):  
Algebraic Variety ◽  
Algebraic Curve ◽  
Technical Tool ◽  
Constant Degree

AbstractWe show that, for a constant-degree algebraic curve γ in ℝD, every set of n points on γ spans at least Ω(n4/3) distinct distances, unless γ is an algebraic helix, in the sense of Charalambides [2]. This improves the earlier bound Ω(n5/4) of Charalambides [2].We also show that, for every set P of n points that lie on a d-dimensional constant-degree algebraic variety V in ℝD, there exists a subset S ⊂ P of size at least Ω(n4/(9+12(d−1))), such that S spans $\left({\begin{array}{*{20}{c}} {|S|} \\ 2 \\\end{array}} \right)$ distinct distances. This improves the earlier bound of Ω(n1/(3d)) of Conlon, Fox, Gasarch, Harris, Ulrich and Zbarsky [4].Both results are consequences of a common technical tool.

One-to-all broadcast algorithm for constant degree 4 Cayley graphs

1999 ◽  
Vol 25 (3) ◽  
pp. 249-264 ◽  
Author(s):  
Mohamed Benmaiza ◽  
Abderezak Touzene
Keyword(s):  
Cayley Graphs ◽  
Constant Degree
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