scholarly journals Open sets in computability theory and reverse mathematics

2020 ◽  
Vol 30 (8) ◽  
pp. 1639-1679
Author(s):  
Dag Normann ◽  
Sam Sanders
Keyword(s):  
Baire Category ◽  
Reverse Mathematics ◽  
Computability Theory ◽  
Characteristic Functions ◽  
Main Question ◽  
Natural Question ◽  
Third Order ◽  
The Subject ◽  
Computational Properties

Abstract To enable the study of open sets in computational approaches to mathematics, lots of extra data and structure on these sets is assumed. For both foundational and mathematical reasons, it is then a natural question, and the subject of this paper, what the influence of this extra data and structure is on the logical and computational properties of basic theorems pertaining to open sets. To answer this question, we study various basic theorems of analysis, like the Baire category, Heine, Heine–Borel, Urysohn and Tietze theorems, all for open sets given by their (third-order) characteristic functions. Regarding computability theory, the objects claimed to exist by the aforementioned theorems undergo a shift from ‘computable’ to ‘not computable in any type 2 functional’, following Kleene’s S1–S9. Regarding reverse mathematics, the latter’s main question, namely which set existence axioms are necessary for proving a given theorem, does not have a unique or unambiguous answer for the aforementioned theorems, working in Kohlenbach’s higher-order framework. A finer study of representations of open sets leads to the new ‘$\varDelta$-functional’ that has unique (computational) properties.

Alan Turing and the Foundations of Computable Analysis

2011 ◽  
Vol 17 (3) ◽  
pp. 394-430 ◽  
Author(s):  
Guido Gherardi
Keyword(s):  
Computability Theory ◽  
Computable Analysis ◽  
Real Numbers ◽  
Machine Model ◽  
Alan Turing ◽  
Real Functions ◽  
The Subject

AbstractWe investigate Turing's contributions to computability theory for real numbers and real functions presented in [22, 24, 26]. In particular, it is shown how two fundamental approaches to computable analysis, the so-called ‘Type-2 Theory of Effectivity’ (TTE) and the ‘realRAM machine’ model, have their foundations in Turing's work, in spite of the two incompatible notions of computability they involve. It is also shown, by contrast, how the modern conceptual tools provided by these two paradigms allow a systematic interpretation of Turing's pioneering work in the subject.

scholarly journals The Aging Vasculature: Glucose Tolerance, Hypoglycemia and the Role of the Serum Response Factor

2021 ◽  
Vol 8 (5) ◽  
pp. 58
Author(s):  
Hazel Aberdeen ◽  
Kaela Battles ◽  
Ariana Taylor ◽  
Jeranae Garner-Donald ◽  
Ana Davis-Wilson ◽  
...  
Keyword(s):  
Glucose Tolerance ◽  
Molecular Mechanisms ◽  
Serum Response Factor ◽  
Response Factor ◽  
Homeostatic Control ◽  
Older Americans ◽  
The Subject ◽  
Serum Response

The fastest growing demographic in the U.S. at the present time is those aged 65 years and older. Accompanying advancing age are a myriad of physiological changes in which reserve capacity is diminished and homeostatic control attenuates. One facet of homeostatic control lost with advancing age is glucose tolerance. Nowhere is this more accentuated than in the high proportion of older Americans who are diabetic. Coupled with advancing age, diabetes predisposes affected subjects to the onset and progression of cardiovascular disease (CVD). In the treatment of type 2 diabetes, hypoglycemic episodes are a frequent clinical manifestation, which often result in more severe pathological outcomes compared to those observed in cases of insulin resistance, including premature appearance of biomarkers of senescence. Unfortunately, molecular mechanisms of hypoglycemia remain unclear and the subject of much debate. In this review, the molecular basis of the aging vasculature (endothelium) and how glycemic flux drives the appearance of cardiovascular lesions and injury are discussed. Further, we review the potential role of the serum response factor (SRF) in driving glycemic flux-related cellular signaling through its association with various proteins.

scholarly journals Analysis of Multiserver Queueing System with Opportunistic Occupation and Reservation of Servers

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Bin Sun ◽  
Moon Ho Lee ◽  
Sergey A. Dudin ◽  
Alexander N. Dudin
Keyword(s):  
System Performance ◽  
Queueing System ◽  
Optimal Choice ◽  
Preemptive Priority ◽  
Rate Dependent ◽  
Service Type ◽  
The Subject ◽  
Multiserver Queueing System

We consider a multiserver queueing system with two input flows. Type-1 customers have preemptive priority and are lost during arrival only if all servers are occupied by type-1 customers. If all servers are occupied, but some provide service to type-2 customers, service of type-2 customer is terminated and type-1 customer occupies the server. If the number of busy servers is less than the thresholdMduring type-2 customer arrival epoch, this customer is accepted. Otherwise, it is lost or becomes a retrial customer. It will retry to obtain service. Type-2 customer whose service is terminated is lost or moves to the pool of retrial customers. The service time is exponentially distributed with the rate dependent on the customer’s type. Such queueing system is suitable for modeling cognitive radio. Type-1 customers are interpreted as requests generated by primary users. Type-2 customers are generated by secondary or cognitive users. The problem of optimal choice of the thresholdMis the subject of this paper. Behavior of the system is described by the multidimensional Markov chain. Its generator, ergodicity condition, and stationary distribution are given. The system performance measures are obtained. The numerical results show the effectiveness of considered admission control.

scholarly journals The Influence of IFRS Adoption

2021 ◽  
Author(s):  
Feng C. Xu
Keyword(s):  
Financial Reporting ◽  
Reporting Quality ◽  
Financial Reporting Quality ◽  
Main Question ◽  
Accounting Disclosure ◽  
Ifrs Adoption ◽  
The Subject

This paper aims to present a thorough theoretical coverage to the subject studied by focusing on the concepts in companies as general, and accounting disclosure, test the selected hypothesis, obtain satisfying results to the research in an appropriate manner that consists with the problem studied and hypotheses, and find a reasonable answer to main question that is (Does IFRS adoption in the large banks improve financial reporting quality?) based on the main hypotheses which are financial reporting quality has not improved after IFRS adoption in the large banks, and financial reporting quality has improved after IFRS adoption in the large banks.

scholarly journals Oscillation and Asymptotic Properties of Differential Equations of Third-Order

Axioms ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 192
Author(s):  
R. Elayaraja ◽  
V. Ganesan ◽  
Omar Bazighifan ◽  
Clemente Cesarano
Keyword(s):  
Differential Equations ◽  
Asymptotic Properties ◽  
Neutral Delay ◽  
Third Order ◽  
Riccati Technique ◽  
Neutral Delay Differential Equations ◽  
The Subject ◽  
Delay Differential ◽  
New Criteria ◽  
Noncanonical Operator

The main purpose of this study is aimed at developing new criteria of the iterative nature to test the asymptotic and oscillation of nonlinear neutral delay differential equations of third order with noncanonical operator (a(ι)[(b(ι)x(ι)+p(ι)x(ι−τ)′)′]β)′+∫cdq(ι,μ)xβ(σ(ι,μ))dμ=0, where ι≥ι0 and w(ι):=x(ι)+p(ι)x(ι−τ). New oscillation results are established by using the generalized Riccati technique under the assumption of ∫ι0ιa−1/β(s)ds<∫ι0ι1b(s)ds=∞asι→∞. Our new results complement the related contributions to the subject. An example is given to prove the significance of new theorem.

Groups and Monoids of Regular Graphs (And of Graphs with Bounded Degrees)

1973 ◽  
Vol 25 (2) ◽  
pp. 239-251 ◽  
Author(s):  
Pavol Hell ◽  
Jaroslav Nešetřil
Keyword(s):  
Category Theory ◽  
Main Question ◽  
Regular Graphs ◽  
Group Of Automorphisms ◽  
Automorphisms Of Graphs ◽  
Usual Manner ◽  
The Subject ◽  
Groups Of Automorphisms

A graph X is a set V(X) (the vertices of X) with a system E(X) of 2-element subsets of V(X) (the edges of X). Let X, Y be graphs and f : V(X) → V(Y) a mapping; then/ is called a homomorphism of X into F if [f(x),f(y)] ∈ E(Y) whenever [x,y] ∈ E(X). Endomorphisms, isomorphisms and automorphisms are defined in the usual manner.Much work has been done on the subject of representing groups as groups of automorphisms of graphs (i.e., given a group G, to find a graph X such that the group of automorphisms of X is isomorphic to G). Recently, this was related to category theory, the main question being as to whether every monoid (i.e., semigroup with 1) can be represented as the monoid of endomorphisms of some graph in a given category of graphs.

scholarly journals IDENTIFIKASI PERMASALAHAN DALAM MENYIMAK BAHASA JEPANG TERKAIT DENGAN BENTUK PILIHAN JAWABAN SOAL YANG DIALAMI MAHASISWA DI BALI

IZUMI ◽  
2015 ◽  
Vol 4 (1) ◽  
pp. 10
Author(s):  
Desak Made Sri Mardani
Keyword(s):  
Fast Response ◽  
The Other ◽  
Main Question ◽  
Listening Test ◽  
Written Form ◽  
The Subject ◽  
Answer Choice ◽  
Different Characteristics

This study aims at investigating the problems in listening test encountered by students of Japanese department in Bali associated with the answer choice of the test. This study was design descriptively in which the subject were 133 Japanese department student of 3rd semester from 3 different universities. The object of this study is the problems encountered by students of Japanese department in Bali associated with the answer choice of the listening test. The result of study showed that the students were easier to answer the test correctly with written form of answer choice. In each main question, it could be seen that the student were easier to find out the answer of ‘fast response’ question than the other main questions. From the analysis of items difficulty it was found that the problems encountered by students in listening were more on items with written answer choice, with different characteristics of the questions.

scholarly journals Top Three Risk Factors of Coronary Artery Disease in Chittagong, Bangladesh

2017 ◽  
Vol 16 (1) ◽  
pp. 26-28
Author(s):  
Abu Tarek Iqbal ◽  
M Jalal Uddin ◽  
Shaikh Md Hasan Mamun ◽  
Rajat Sankar Roy Biswas
Keyword(s):  
Risk Factors ◽  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Age Group ◽  
Primordial Prevention ◽  
Male Preponderance ◽  
The Subject ◽  
Artery Disease ◽  
Type 2 Diabetic

Background: Many studies were conducted on the subject in home and abroad but there is none in Chittagong, Bangladesh. To know about top three risk factors for coronary artery disease we conducted the study.Methods: It was a retrospective study. Records of a private cardiac center from July 2013 to June 2014 was collected. Only coronary stenosed cases (As per angiogram) was studied. Age, sex, BMI, diabetes mellitus, hypertension, smoking and other risk factors were considered. Collected data was managed manually. Finally discussion was made and conclusion was done.Results: Majority cases 58(76%) were of 40-60 years age group. Male preponderance was there 64(83%). BMI of 45(60%) cases was normal (<25). Family history was positive among 11(14%) cases. Dyslipidemia was found in 08(10%) cases, 56(73%) cases were hypertensive, 43(56%) cases were type-2 diabetic and 35(45%) were smoker.Conclusion: Hypertension, Diabetes and Smoking are top 03 risk factors for coronary artery disease. All are modifiable. So, primordial prevention should be taken to reduce prevalence of coronary artery disease.Chatt Maa Shi Hosp Med Coll J; Vol.16 (1); Jan 2017; Page 26-28

scholarly journals Reverse mathematics, computability, and partitions of trees

2009 ◽  
Vol 74 (1) ◽  
pp. 201-215 ◽  
Author(s):  
Jennifer Chubb ◽  
Jeffry L. Hirst ◽  
Timothy H. McNicholl
Keyword(s):  
Binary Tree ◽  
Reverse Mathematics ◽  
Computability Theory ◽  
Ramsey's Theorem ◽  
Ramsey’S Theorem

AbstractWe examine the reverse mathematics and computability theory of a form of Ramsey's theorem in which the linear n-tuples of a binary tree are colored.

scholarly journals XII. Studies on biogenesis

1874 ◽  
Vol 164 ◽  
pp. 457-477 ◽  
Keyword(s):  
De Novo ◽  
Main Question ◽  
The Media ◽  
The Subject

The question of the origin of Bacteria and Torulœ lies so deeply at the root of some of the most important problems, not only of biology, but of pathology and practical therapeutics, that I make no apology for bringing forward the fruits of another investigation on the subject. The main question in controversy is whether these organisms originate de novo in the media where they grow, or whether they spring, like higher beings, from germs or parents like themselves.

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