scholarly journals A Faster Tree-Decomposition Based Algorithm for Counting Linear Extensions

Algorithmica ◽  
2019 ◽  
Vol 82 (8) ◽  
pp. 2156-2173 ◽  
Author(s):  
Kustaa Kangas ◽  
Mikko Koivisto ◽  
Sami Salonen
Keyword(s):  
Point Of View ◽  
The Other ◽  
Tree Decomposition ◽  
Statistical Regression ◽  
Linear Extensions ◽  
Time Data ◽  
Practical Point ◽  
Running Time ◽  
Fast Multiplication ◽  
Cover Graph

Abstract We investigate the problem of computing the number of linear extensions of a given n-element poset whose cover graph has treewidth t. We present an algorithm that runs in time $${\tilde{O}}(n^{t+3})$$ O ~ ( n t + 3 ) for any constant t; the notation $${\tilde{O}}$$ O ~ hides polylogarithmic factors. Our algorithm applies dynamic programming along a tree decomposition of the cover graph; the join nodes of the tree decomposition are handled by fast multiplication of multivariate polynomials. We also investigate the algorithm from a practical point of view. We observe that the running time is not well characterized by the parameters n and t alone: fixing these parameters leaves large variance in running times due to uncontrolled features of the selected optimal-width tree decomposition. We compare two approaches to select an efficient tree decomposition: one is to include additional features of the tree decomposition to build a more accurate, heuristic cost function; the other approach is to fit a statistical regression model to collected running time data. Both approaches are shown to yield a tree decomposition that typically is significantly more efficient than a random optimal-width tree decomposition.

scholarly journals The theory of photographic processes, part II: On the chemical dynamics of development, including the microscopy of the image

1905 ◽  
Vol 76 (509) ◽  
pp. 217-234 ◽  
Keyword(s):  
Heterogeneous Systems ◽  
Point Of View ◽  
The Other ◽  
Chemical Dynamics ◽  
Practical Point ◽  
Previous Communication ◽  
The One

The investigation of development described in a previous communication was extended by the application of microscopic methods. The fact that both the silver haloid and the resulting silver are distributed through the film in the form of particles of minute but measurable size, allows us in this way to detect finer qualitative differences in, and to draw independent deductions on the processes of exposure and development. The size of the grain is important, both from the practical point of view and from the theoretical: in the one case as bearing on spectroscopical and astronomical photography, in the other on account of the great importance of the degree of surface-extension for heterogeneous systems. The method has been used previously by Abney, Abegg, Kaiserling, Ebert, and others, but by far the most systematic and important inquiry is that of K. Schaum and V. Bellach.

A PEDIATRIC-PSYCHIATRIC VIEWPOINT ON OBESITY

PEDIATRICS ◽  
1957 ◽  
Vol 20 (3) ◽  
pp. 552-556
Author(s):  
Reginald S. Lourie
Keyword(s):  
Point Of View ◽  
The Other ◽  
Structural Elements ◽  
Practical Point ◽  
The Third ◽  
History Of ◽  
Gastric Mucous ◽  
History Of Obesity ◽  
Excessive Quantity ◽  
Layer Concept

FROM the viewpoint of the pediatric psychiatrist, the problems of obesity, as seen clinically, can be thought of as having three layers. The first is constitutional, better described as physiologic, which may be broken down into genetic and structural elements. The second is psychologic, consisting of the values that food intake or the obesity itself come to have. The third layer is made of the cultural and social reactions to food and fat. These attitudes encountered inside and outside the home intermesh in their effects with the physiologic and psychologic levels. These, in turn, are also interwoven, until one cannot separate one layer from the other. However, when individual cases are scrutinized they reveal the pathology at one layer or the other to predominate and indicate where efforts to modify the abnormality might best be directed. Incidentally, the same levels operate on the other side of the coin, anorexia. From the practical point of view, let us consider the natural history of obesity and the clinical varieties one sees in practice, and let us see how the three-layer concept fits. First, as pointed out by Gordon, there is a tendency to be complacent or even pleased with obese infants. At level one, the physiologic, such constitutional factors as those present in the neonate born with an excessive quantity of pepsinogen secreted by the gastric mucous membrane could have the effect of producing as Mirsky points out, a relatively intense or even continuous hunger, and make greater demands on its mother for nursing.

Application of Mechanical Vibration in the Machine Building Technology

2012 ◽  
Vol 504-506 ◽  
pp. 1383-1388 ◽  
Author(s):  
Piotr Sędek ◽  
Marek Stanisław Węglowski
Keyword(s):  
Dimensional Stability ◽  
Mechanical Vibration ◽  
Machine Building ◽  
Point Of View ◽  
The Other ◽  
Practical Point ◽  
Building Technology ◽  
Technological Stresses ◽  
External Loads ◽  
Technological Stress

The application of mechanical vibration has been known for many years, but some controversy still exists. According to some ideas the mechanical vibration reduces the technological stresses by summation of technological stress and stress from external loads (vibration). But on the other hand, the mechanical vibration causes more complicated phenomena (micro-relaxation) resulting in dimensional stability close to natural seasoning effects. In the present study authors present results of research into mechanical vibration from the experimental and practical point of view, proving that this process can be used to obtain dimensional stability. The results has also indicated that the reduction of the technological stresses is highly questionable.

scholarly journals Economic Efficiency in Economic Analysis of Law

2017 ◽  
Vol 3 (15) ◽  
Author(s):  
Tomasz Famulski
Keyword(s):  
Economic Efficiency ◽  
Critical Analysis ◽  
Point Of View ◽  
The Other ◽  
Legal Regulations ◽  
Economic Analysis Of Law ◽  
Practical Point ◽  
A Value ◽  
The Law ◽  
Fundamental Value

The aim of the article is to identify the category of economic efficiency on the grounds of L&E. According to the primary thesis of L&E economic efficiency is a fundamental legal value. The study discusses said thesis. On one hand, the controversy surrounding the thesis stem from lack of its unequivocal understanding. On the other, law has been functioning for centuries, while the question of its economic efficiency has only been raised for a few decades. Fundamental value, which has always been associated with law, is justice. It follows that the issue of various approaches to the relation between economic efficiency and justice in L&E is considered. Critical analysis of the literature allows to formulate arguments for and against each of these values in enacting and enforcing the law. Significant differences in various approaches to this matter are identified. Simultaneously, the assumption that efficiency is a value realized in the law beside justice is considered to be correct. The issue raised is important from the practical point of view. A theoretical consensus would support formulating a model, which would allow assessment of legal regulations based on criteria of economic efficiency and justice.

Increasing data security by data compression

2005 ◽  
Vol 42 (4) ◽  
pp. 343-353
Author(s):  
Tibor Nemetz ◽  
Pál Papp
Keyword(s):  
Data Compression ◽  
Data Security ◽  
Cryptographic Protocols ◽  
Point Of View ◽  
The Other ◽  
Negative Effects ◽  
Practical Point

We analyze the effect of data-compression on security of encryption both from theoretical and practical point of view. It is demonstrated that data-compression essentially improves the security of encryption, helps to overcome technical difficulties. On the other side, it makes crypt-analysis more difficult and causes extra problems. At present data-compression applied rarely and frequently defectively. We propose a method which eliminates the negative effects. Our aim is initiate data compression as an aid for data security. To this end we provide an overview of the most frequently used cryptographic protocols. A comparison with encryption software reveals that even the most frequently used protocols do not support encryption and compression.

Exploring knowledge visualization in the digital age: an analysis of benefits and risks

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ciro Troise
Keyword(s):  
Absorptive Capacity ◽  
Stakeholder Engagement ◽  
Design Methodology ◽  
Digital Age ◽  
Second Order ◽  
Point Of View ◽  
The Other ◽  
Knowledge Visualization ◽  
Content Type ◽  
Practical Point

PurposeThe purpose of this paper is to explore the main benefits and risks of knowledge visualization in the current digital age.Design/methodology/approachThe paper is based on a qualitative and explorative research to frame the benefits and risks of knowledge visualization. The emerging views of 57 small and medium-sized entrepreneurs (SMEs) managers are examined.FindingsThe findings reveal both benefits and risks related to knowledge visualization. The two aggregate dimensions (i.e. benefits and risks) are supported by six second-order and five second-order categories, respectively. On one side, the main benefits highlighted in the study are related to: stakeholder engagement, flexibility, knowledge transfer, signaling role, agility and interactivity; on the other side, the risks identified are related to: complexity, absorptive capacity, divergences, capabilities and ineffectiveness.Originality/valueThe research highlights novel insights in the emerging field of knowledge visualization and extends current literature. It provides useful implication from both a theoretical and practical point of view.

scholarly journals The annealing of copper: with special reference to dilatation

1907 ◽  
Vol 80 (535) ◽  
pp. 1-12
Keyword(s):  
Common Knowledge ◽  
Point Of View ◽  
The Other ◽  
Annealed Condition ◽  
Practical Point ◽  
Special Cases ◽  
Soft State ◽  
Rate Of Cooling ◽  
The Difference ◽  
Annealed Copper

It is well known that copper is met with in two distinct forms, viz., the soft state as in cast or annealed metal, and the hard variety which is the result ofmechanical work. There is more difference between the mechanical properties of hard and of soft copper than is observed in the case of two distinct metals; such, for example, as nickel and cobalt. For instance, one of the most important of these differences, from a practical point of view, is in connection with the tensile strength of the material, which is only about 10 to 14 tons per square inch in cast or in annealed copper, while in hardened copper the tenacity is about twice as great, and usually runs from about 20 to 28 tons per square inch, or even more in special cases. The difference between hard and soft copper can be also readily illustrated by bending two rods about ¼ inch square section, one in the hardened and the other in the annealed condition. The latter can be easily bent in the hands or even tied in a knot, while the mechanically worked bar is rigid and elastic, and can only be bent by the application of considerable force. It is common knowledge that hard copper becomes perfectly annealed by heating to 500° C,; that the heating need not be for any lengthened period, and the rate of cooling afterwards is unimportant.

Ownership of Organs Taken From a Living Person

1993 ◽  
Vol 27 (4) ◽  
pp. 624-651
Author(s):  
Gad (Guido) Tedeschi
Keyword(s):  
Bone Marrow ◽  
Point Of View ◽  
The Body ◽  
The Other ◽  
Practical Point ◽  
Living Body ◽  
The Past ◽  
Legal Questions ◽  
Living Person ◽  
Different Sources

Medical recourse to organ transplants and the transfer of other material from the body of one person to that of another has increased steadily over the past few decades. This raises new legal questions, and brings once-thought purely academic questions to the forefront.Organs and other material used for transplants can either be taken from a living person (for example, bone marrow, sperm, or blood); or from a corpse, as is the case with most transplants. Certain material, in particular kidneys, can be taken from both. In Israeli law, this duality in the sources of supply is paralleled by different sources of regulation. With respect to a corpse, the Anatomy and Pathology Law attempts to solve the main problems from a practical point of view. On the other hand, the Israeli legislator has as yet to intervene with respect to the living body.

scholarly journals Solomon Echoes Extended to Soft Pulse Excitation

1994 ◽  
Vol 49 (1-2) ◽  
pp. 89-96 ◽  
Author(s):  
Pascal P. Man
Keyword(s):  
Pulse Length ◽  
Point Of View ◽  
The Other ◽  
Pulse Excitation ◽  
Practical Point ◽  
First Order ◽  
Central Transition ◽  
Quadrupolar Coupling ◽  
Amplitude Versus ◽  
Radiofrequency Pulse

AbstractSolomon echoes, produced by two in-phase pulses separated by a delay τ2, are derived in taking into account the first-order quadrupolar interaction during the pulses. Consequently, the results are valid for any ratio of the quadrupolar coupling, ωQ, to the amplitude of the radiofrequency pulse, ωRF. Six echoes are predicted after the second pulse: three, detected as inner satellite signals, occur at τ4 = τ2, τ4 =2 τ2 and τ4 = 3 τ2/2; the other three, detected as outer satellite signals, occur at τ4=τ2/2, τ4 =τ2 , and τ4=3τ2/2. These echoes originate from the refocusing of single- and multi-quantum offresonance coherences developed during the first pulse. Four of them are allowed echoes, the other two are forbidden ones. However, there is no echo for the central transition. From a practical point of view this means that τ2 must be short compared to τFID, the duration of the FID of the central transition. The behavior of the echo amplitude versus the second pulse length is discussed for several ratios of ωQ/ωRF.

scholarly journals Narcolepsy Treatment: Present and Future

2021 ◽  
Author(s):  
Juan José Ortega-Albás ◽  
Raquel López García ◽  
Alfonso Martínez Martínez ◽  
Sonia Carratalá Monfort ◽  
Juan Antonio Royo Prats ◽  
...  
Keyword(s):  
Stem Cell ◽  
Stem Cell Transplantation ◽  
Diagnostic Delay ◽  
Gene Replacement ◽  
Point Of View ◽  
The Other ◽  
Practical Point ◽  
Social Events ◽  
Gene Replacement Therapy ◽  
Future Treatments

Narcolepsy is a chronic, disabling sleep disorder with a significant diagnostic delay. Nowadays, treatment is focused on managing symptoms that impacts patient’s life, such as at workplace, social events or even at school, but not aimed cure the disease. However, we have pharmacological treatments that effectively help control the main symptoms (excessive daytime sleepiness, cataplexy, fragmentation of nocturnal sleep, sleep paralysis and hypnagogic and hypnopompic hallucinations). On the other hand, pharmacological treatment must be individualised as there are great variations in severity, order of appearance symptoms and development of the disease. We intend to expose the different symptomatic treatments recommended by clinical guidelines and the clinical management from a practical point of view. Future treatments include therapies based on the replacement of hypocretin or the administration of agonist receptors. Other techniques such as hypothalamic stem cell transplantation, gene replacement therapy or immunotherapy are also being investigated.

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