scholarly journals Stack Sorting with Increasing and Decreasing Stacks

10.37236/9154 ◽  
2020 ◽  
Vol 27 (1) ◽  
Author(s):  
Giulio Cerbai ◽  
Lapo Cioni ◽  
Luca Ferrari
Keyword(s):  
The Other ◽  
Sorting Algorithm ◽  
Sorting Machine ◽  
Infinite Basis ◽  
Open Questions ◽  
Stack Sorting ◽  
In Series

We introduce a sorting machine consisting of $k+1$ stacks in series: the first $k$ stacks can only contain elements in decreasing order from top to bottom, while the last one has the opposite restriction. This device generalizes the $\mathfrak{DI}$ machine introduced by Rebecca Smith, which studies the case $k=1$. Here we show that, for $k=2$, the set of sortable  permutations is a class with infinite basis, by explicitly finding an antichain of minimal nonsortable permutations. This construction can easily be adapted to each $k\geqslant 3$. Next we describe an optimal sorting algorithm, again for the case $k=2$. We then analyze two types of left-greedy sorting procedures, obtaining complete results in one case and only some partial results in the other one. We close the paper by discussing a few open questions.

VII.–The Effect of the Transport of Heat on the Rate of Evaporation of Small Droplets I. Evaporation into a Large Excess of a Gas

1962 ◽  
Vol 66 (2) ◽  
pp. 65-80
Author(s):  
P. G. Wright
Keyword(s):  
Gaseous Phase ◽  
The Other ◽  
Total Resistance ◽  
Large Excess ◽  
Stationary Growth ◽  
In Series ◽  
Finite Period ◽  
Rate Of Evaporation ◽  
Latent Heat Of Vaporization ◽  
Algebraic Formulation

SynopsisBeginning with fundamental results obtained by Mason for the effect of self-cooling on the evaporation of drops, and by Fuchs for the diffusional retardation of evaporation for small droplets of any radius, explicit expressions for the effect of the transport of heat on the rate of quasi-stationary growth or evaporation, are discussed.The simplest algebraic formulation of the results lends itself to interpretation as expressing a resistance to evaporation, the total resistance being the sum of four resistances in series. Two of these resistances, one to diffusion and one to the conduction of heat, are offered by the gaseous phase in bulk; and there are two corresponding resistances at the interface. Corrections are formulated for the effect of the heating of the droplet by radiation. These corrections may be expressed as a (finite) resistance in parallel with the other two resistances to the transfer of heat. Simplified equations are obtained for the evaporation of a liquid whose latent heat of vaporization is very large.Some remarks are made on the formation of a monodisperse aerosol by the growth of smaller droplets. Integrated expressions are obtained for particular cases of the evaporation of a droplet over a finite period of time.

Combinatorial principles weaker than Ramsey's Theorem for pairs

2007 ◽  
Vol 72 (1) ◽  
pp. 171-206 ◽  
Author(s):  
Denis R. Hirschfeldt ◽  
Richard A. Shore
Keyword(s):  
Reverse Mathematics ◽  
The Other ◽  
Base System ◽  
Ramsey's Theorem ◽  
Open Questions ◽  
Ramsey’S Theorem ◽  
Combinatorial Principles ◽  
Points Of View ◽  
The One ◽  
Infinite Linear

AbstractWe investigate the complexity of various combinatorial theorems about linear and partial orders, from the points of view of computability theory and reverse mathematics. We focus in particular on the principles ADS (Ascending or Descending Sequence), which states that every infinite linear order has either an infinite descending sequence or an infinite ascending sequence, and CAC (Chain-AntiChain), which states that every infinite partial order has either an infinite chain or an infinite antichain. It is wellknown that Ramsey's Theorem for pairs () splits into a stable version () and a cohesive principle (COH). We show that the same is true of ADS and CAC, and that in their cases the stable versions are strictly weaker than the full ones (which is not known to be the case for and ). We also analyze the relationships between these principles and other systems and principles previously studied by reverse mathematics, such as WKL0, DNR, and BΣ2. We show, for instance, that WKL0 is incomparable with all of the systems we study. We also prove computability-theoretic and conservation results for them. Among these results are a strengthening of the fact, proved by Cholak, Jockusch, and Slaman, that COH is -conservative over the base system RCA0. We also prove that CAC does not imply DNR which, combined with a recent result of Hirschfeldt, Jockusch. Kjos-Hanssen, Lempp, and Slaman, shows that CAC does not imply (and so does not imply ). This answers a question of Cholak, Jockusch, and Slaman.Our proofs suggest that the essential distinction between ADS and CAC on the one hand and on the other is that the colorings needed for our analysis are in some way transitive. We formalize this intuition as the notions of transitive and semitransitive colorings and show that the existence of homogeneous sets for such colorings is equivalent to ADS and CAC, respectively. We finish with several open questions.

Analisis Kinerja Algoritma Quick Double Merge Sort Paralel Menggunakan openMP

2020 ◽  
Vol 11 (2) ◽  
pp. 95-102
Author(s):  
I Nyoman Aditya Yudiswara ◽  
Abba Suganda
Keyword(s):  
Parallel Algorithms ◽  
The Other ◽  
Sorting Algorithm ◽  
Data Parallelism ◽  
Parallel Sorting ◽  
Sequential Algorithms ◽  
Sorting Algorithms ◽  
Merge Sort ◽  
Sort Algorithm ◽  
Quick Sort

Processor technology currently tends to increase the number of cores more than increasing the clock speed. This development is very useful and becomes an opportunity to improve the performance of sequential algorithms that are only done by one core. This paper discusses the sorting algorithm that is executed in parallel by several logical CPUs or cores using the openMP library. This algorithm is named QDM Sort which is a combination of sequential quick sort algorithm and double merge algorithm. This study uses a data parallelism approach to design parallel algorithms from sequential algorithms. The data used in this study are the data that have not been sorted and also the data that has been sorted is integer type which is stored in advance in a file. The parameter measured to determine the performance of the QDM Sort algorithm is speedup. In a condition where a large amount of data is above 4096 and the number of threads in QDM Sort is the same as the number of logical CPUs, the QDM Sort algorithm has a better speedup compared to the other parallel sorting algorithms discussed in this study. For small amounts of data it is still better to use sequential sorting algorithm.

scholarly journals Socio-political-environmental perceptions of participants in the public hearings of the Brazilian Representative House on Environment

2021 ◽  
Vol 24 ◽  
Author(s):  
Antonio Teixeira de Barros
Keyword(s):  
Sustainable Development ◽  
The Other ◽  
Government Agencies ◽  
Environmental Perceptions ◽  
The Public ◽  
Other Hand ◽  
Open Questions ◽  
Public Hearings ◽  
Chamber Of Deputies

Abstract The article analyzes the perceptions of the citizens who participated in the public hearings promoted by the Committee on Environment and Sustainable Development (CMADS) of the Chamber of Deputies during the year 2018. The methodology consisted in the use of a questionnaire with open and closed questions applied to a sample of 71.22% of the public that was present at these events. For the study of perceptions, open questions are particularly relevant, since they consist of arguments, analyzes and justifications presented by citizens, based on the experience of participating. The conclusions show that a diversity of citizens’ perceptions of the CMADS agenda, the topics under debate and the participation of technicians and representatives of entities from the environmental field. On the other hand, there are critical opinions in relation to the performance of parliamentarians, representatives of government agencies and the dynamics of debates.

The Frequency of Pericardial Effusions in Bacterial Meningitis

PEDIATRICS ◽  
1979 ◽  
Vol 63 (5) ◽  
pp. 764-770
Author(s):  
W. Pennock Laird ◽  
John D. Nelson ◽  
F. Douglas Huffines
Keyword(s):  
Risk Factors ◽  
Bacterial Meningitis ◽  
Antibiotic Therapy ◽  
Significant Risk ◽  
Literature Survey ◽  
The Other ◽  
Purulent Pericarditis ◽  
Pericardial Effusions ◽  
In Series ◽  
A Prospective Study

Because of our experience with four cases of purulent pericarditis complicating bacterial meningitis during a 13-month period, we performed a prospective study to determine the frequency of this complication. Echocardiograms were done on 100 patients with bacterial meningitis. Small or moderate pericardial effusions were detected in 19 patients, but none had symptoms or signs related to the effusion. Pericardiocentesis was done in one infant; all the other effusions resolved spontaneously. Patients with effusion were significantly younger than those without this complication, but no other significant risk factors were identified. A literature survey indicated that symptomatic pericarditis occurs in fewer than 1% of patients with meningitis. Conversely, in series of cases of purulent pericarditis, associated meningitis was reported in 12% of patients. We concluded that pericardial infection is common in patients with meningitis but that it is usually of no clinical significance and resolves with antibiotic therapy.

Password Recovery Research and its Future Direction

2012 ◽  
pp. 192-206
Author(s):  
Vrizlynn L. L. Thing ◽  
Hwei-Ming Ying
Keyword(s):  
Human Nature ◽  
Digital Forensics ◽  
The Other ◽  
Sorting Algorithm ◽  
Other Hand ◽  
Rainbow Table ◽  
Password Protection ◽  
Recovery Performance ◽  
Time Memory Tradeoff ◽  
Future Direction

As users become increasingly aware of the need to adopt strong password, it brings challenges to digital forensics investigators due to the password protection of potential evidentiary data. On the other hand, due to human nature and their tendency to select memorable passwords, which compromises security for convenience, users may select strong passwords by considering a permutation of dictionary words. In this chapter, the authors discuss the existing password recovery methods and identify promising password recovery approaches. They also present their previous work on the design of a time-memory tradeoff pre-computed table coupled with a new sorting algorithm, and its two new storage mechanisms. The results on the evaluation of its password recovery performance are also presented. In this chapter, the authors propose the design of a new password recovery table by integrating the construction of common passwords within the enhanced rainbow table to incorporate the two promising password recovery approaches. They then present the theoretical proof of the feasibility of this technique.

The diffusion of load from a stiffener into an infinite elastic sheet

1957 ◽  
Vol 239 (1218) ◽  
pp. 296-310 ◽  
Keyword(s):  
Mixed Boundary ◽  
Functional Differential Equations ◽  
Mixed Boundary Conditions ◽  
Limited Range ◽  
The Other ◽  
Shear Stresses ◽  
Variable Theory ◽  
Elastic Sheet ◽  
Complex Variable Theory ◽  
In Series

The use of complex variable theory to express problems in generalized plane stress is well known, but methods of finding particular solutions are available for only a limited range of problems. This paper and its sequel will develop a new technique, reducing certain problems with mixed boundary conditions to second order functional differential equations, whose solutions can be found in series form. Exact solutions are given to three fundamental problems of the diffusion of load in an infinite two-dimensional elastic sheet to which a semi-infinite elastic stiffener is continuously attached throughout its length. The first problem has a load applied to the end of the stiffener, with its line of action along the stiffener and its reactions at infinity. In the other two problems the stiffener end is unloaded but a uniform tension is applied to the sheet at infinity, in one case parallel to the stiffener, in the other perpendicular to it. Expressions for the load in the stiffener and for the direct and shear stresses in the sheet are found and plotted in non-dimensional form.

Reliability and barrier assessment of series–parallel systems subject to cascading failures

2020 ◽  
Vol 234 (3) ◽  
pp. 455-469 ◽  
Author(s):  
Lin Xie ◽  
Mary Ann Lundteigen ◽  
Yiliu Liu
Keyword(s):  
Block Diagram ◽  
Parallel Systems ◽  
The Other ◽  
Cascading Failures ◽  
Practical Case ◽  
Aggregation Method ◽  
Safety Barriers ◽  
Parallel Structures ◽  
In Series ◽  
Technical Systems

Cascading failures can occur in many technical systems where the components are organized as in series–parallel structures. The failures in these systems may propagate from one component to the other, not only within the same parallel sub-structure but also between different sub-structures. This article presents a recursive aggregation method based on the extended models of reliability block diagram, for analyzing the impacts of cascading failures on the reliability of series–parallel systems. Based on the reliability analysis, the effects of safety barriers on preventing cascading failures are studied, and the importance of safety barriers at different locations is evaluated. One simple example of three components and one practical case from an oil production system are presented. The findings in these case studies illustrate how system designers and safety managers can identify the effective and reasonable ways of installing safety barriers by using the proposed approaches, for the mitigation of cascading failures in series–parallel technical systems.

scholarly journals Properties of the Fine Granular Area and Postulated Models for Its Formation during Very High Cycle Fatigue—A Review

2020 ◽  
Vol 10 (23) ◽  
pp. 8475
Author(s):  
Jan Patrick Sippel ◽  
Eberhard Kerscher
Keyword(s):  
Fatigue Strength ◽  
Crack Initiation ◽  
Crack Growth ◽  
High Performance ◽  
High Cycle Fatigue ◽  
The Other ◽  
Cycle Fatigue ◽  
Very High Cycle Fatigue ◽  
Open Questions ◽  
Very High

Understanding the mechanisms leading to very high cycle fatigue is necessary to make predictions about the behavior under various conditions and to ensure safe design over the whole lifetime of high-performance components. It is further vital for the development of possible measures to increase the very high cycle fatigue strength. This review therefore intends to give an overview of the properties of the fine granular area that have been observed so far. Furthermore, the existing models to describe the early crack initiation and crack growth within the very high cycle fatigue regime are outlined and the models are evaluated on the basis of the identified fine granular area properties. The aim is to provide an overview of the models that can already be considered refuted and to specify the respective open questions regarding the other individual models.

Larval development of ovine Neostrongylus linearis in four experimentally infected mollusc species

1994 ◽  
Vol 68 (3) ◽  
pp. 207-210 ◽  
Author(s):  
M.Y. Manga-González ◽  
M.P. Morrondo-Pelayo
Keyword(s):  
Post Infection ◽  
The Other ◽  
Snail Species ◽  
Intermediate Hosts ◽  
Cepaea Nemoralis ◽  
In Series ◽  
Mollusc Species ◽  
Higher Temperature ◽  
The One ◽  
First Time

AbstractDevelopment of Neostrongylus linearis larvae was studied in the snail intermediate hosts Oestophora (Oestophora) barbula, Oestophorella buvinieri, Cepaea nemoralis and Helix (Cryptomphalus) aspersa. The molluscs of each species, all adults, were divided into groups of 40 for infection purposes. The infection doses for the first two snail species were 90 and 50 first stage larvae (L1) of N. linearis, respectively. For C. nemoralis two batches were tested: one with 200 L1 kept at 19°C and the other with 250 L1 at a temperature of 21°C. The same was done with Helix (C.) aspersa with 200 L1 at a temperature of 21°C, on the one hand and 300 L1 at 24°C on the other. One or two molluscs of each species were killed in series from the 6th day post-infection (p.i.) until the 44th. Percentage values for total larvae (1, 2 and 3) and L3 were higher with the lower dose for C. nemoralis, whilst the same was true with the higher dose in Helix (C.) aspersa. In both cases, the higher temperature appeared to contribute to cycle acceleration. Using one way analysis of variance, statistically significant differences were detected between the species of molluscs tested concerning percentages of L1 which penetrated, total larvae and L3. According to our results, the decreasing order of susceptibility of these species of molluscs as experimental intermediate hosts of N. linearis is: O. buvinieri, Oestophora (O.) barbula, C. nemoralis and Helix (C.) aspersa. It is the first time that Oestophora (O.) barbula and Oestophorella buvinieri have been named as experimental intermediate hosts of N. linearis.

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