BEING LOW ALONG A SEQUENCE AND ELSEWHERE

2019 ◽  
Vol 84 (02) ◽  
pp. 497-516
Author(s):  
WOLFGANG MERKLE ◽  
LIANG YU
Keyword(s):  
A Priori ◽  
Expected Value ◽  
Infinite Subset ◽  
Additive Constant ◽  
Almost All ◽  
The Given ◽  
Infinite Set ◽  
A Priori Probability

AbstractLet an oracle be called low for prefix-free complexity on a set in case access to the oracle improves the prefix-free complexities of the members of the set at most by an additive constant. Let an oracle be called weakly low for prefix-free complexity on a set in case the oracle is low for prefix-free complexity on an infinite subset of the given set. Furthermore, let an oracle be called low and weakly for prefix-free complexity along a sequence in case the oracle is low and weakly low, respectively, for prefix-free complexity on the set of initial segments of the sequence. Our two main results are the following characterizations. An oracle is low for prefix-free complexity if and only if it is low for prefix-free complexity along some sequences if and only if it is low for prefix-free complexity along all sequences. An oracle is weakly low for prefix-free complexity if and only if it is weakly low for prefix-free complexity along some sequence if and only if it is weakly low for prefix-free complexity along almost all sequences. As a tool for proving these results, we show that prefix-free complexity differs from its expected value with respect to an oracle chosen uniformly at random at most by an additive constant, and that similar results hold for related notions such as a priori probability. Furthermore, we demonstrate that on every infinite set almost all oracles are weakly low but are not low for prefix-free complexity, while by Shoenfield absoluteness there is an infinite set on which uncountably many oracles are low for prefix-free complexity. Finally, we obtain no-gap results, introduce weakly low reducibility, or WLK-reducibility for short, and show that all its degrees except the greatest one are countable.

scholarly journals Bayesian statistics in human genetics

2020 ◽  
Vol 26 ◽  
pp. 316-319
Author(s):  
L. A. Atramentova
Keyword(s):  
Genetic Counseling ◽  
Posterior Probability ◽  
Bayesian Method ◽  
Human Genetics ◽  
Classical Method ◽  
A Priori ◽  
Genetic Data ◽  
Bayes Method ◽  
The Given ◽  
A Priori Probability

Using of the Bayes’ method in genetic counseling allows clarifying of the probability of a disease in the offspring, which in some cases can save probands from additional laboratory diagnostic tests due to the extremely low risk which can be calculated. The article is devoted to the usage of the Bayes’ method in human genetics. The concepts of a priori, conditional, total and posterior probabilities are introduced. As an example, a pedigree with a monogenic recessive X-linked trait is considered. An algorithm for calculating of the probability that a patient is a carrier of a pathological gene is presented. The prediction of results made with help of using the classical method of calculations and the Bayesian method are compared. An example for calculation of the gene mutation rate based on epidemiological and genetic data is given. The discussed topic can be taken into account for presenting of courses in human genetics and medical genetics at classical and medical universities, and the given problem can serve as an example for drawing up of tasks for students with pedigrees of various configurations and other attributes. Keywords: Bayesian method, a priori probability, posterior probability, teaching of genetics, genetic counseling.

Deskripsi Kesulitan Belajar Siswa Berdasarkan Karakteristik Lerner dalam Menyelesaikan Soal Geometri

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Nazom Murio ◽  
Roseli Theis
Keyword(s):  
Qualitative Research ◽  
Visual Perception ◽  
Learning Difficulties ◽  
Research Subjects ◽  
Visual Objects ◽  
Almost All ◽  
Personality Classification ◽  
The Given ◽  
Classification Test ◽  
Descriptive Qualitative

Geometri adalah bagian matematika yang sangat dekat dari siswa, karena hampir semua objek visual yang ada di sekitar siswa adalah objek geometri, tetapi tidak semua siswa menyukai pembelajaran yang menyertakan gambar, sehingga memungkinkan siswa mengalami kesulitan dalam belajar geometri. Tujuan dari penelitian ini adalah untuk menggambarkan kesulitan belajar siswa berdasarkan karakteristik Lerner dalam menyelesaikan pertanyaan geometri. Jenis penelitian ini adalah penelitian deskriptif kualitatif. Subjek penelitian adalah siswa dengan kepribadian wali yang mengalami kesulitan belajar di kelas IX A SMP N 30 Muaro Jambi. Instrumen yang digunakan dalam penelitian ini adalah penulis sendiri, lembar tes klasifikasi kepribadian, lembar tes kesulitan belajar, dan pedoman wawancara. Hasil penelitian menunjukkan siswa dengan kepribadian wali yang mengalami kesulitan belajar, 100% mengalami kelainan persepsi visual, di mana siswa mengalami kesulitan dalam menentukan seperti apa bangun datar pada masalah tersebut. 60% mengalami kesulitan mengenali dan memahami simbol, di mana siswa melihat simbol "//" sebagai simbol untuk kesesuaian. Serta 40% mengalami kesulitan dalam bahasa dan membaca, di mana siswa kesulitan dalam memahami pertanyaan yang diberikan.   Geometry is a very close mathematical part of the student, because almost all visual objects that exist around the students are objects of geometry, but not all students like learning that includes images, thus allowing students to have difficulty in learning geometry. The purpose of this research is to describe students' learning difficulties based on Lerner's characteristic in solving the geometry question. This type of research is descriptive qualitative research. Research subjects were students with guardian personality who had difficulty studying in class IX A SMP N 30 Muaro Jambi. Instruments used in this study are the authors themselves, personality classification test sheets, learning difficulties test sheets, and interview guidelines. The results showed students with guardian personality who experienced learning difficulties, 100% experienced visual perception abnormalities, where students have difficulty in determining what kind of flat wake on the matter. 60% have difficulty recognizing and understanding symbols, where students see the symbol "//" as a symbol for conformity. As well as 40% have difficulty in language and reading, where students difficulty in understanding the given question.

Be Careful, if You Learn Geography for 8th Grade with „Ucha.se“

2021 ◽  
Vol 30 (1) ◽  
pp. 37-53
Author(s):  
Ivan Drenovski ◽  
Keyword(s):  
Test Items ◽  
Educational Site ◽  
8Th Grade ◽  
Basic Concepts ◽  
Almost All ◽  
The Given

The article analyses the content of the video lessons and corresponding to them test items in Geography and Economics for 8 th grade, available for a fee, on the educational site "Ucha.se". The studied curriculum is related to the introduction of basic concepts and explanations of key processes studied by geology, geophysics, astronomy, geochemistry, geomorphology, meteorology, climatology, hydrology, biology and other sciences. There are serious lapses in the scientific reliability and correctness of the given statements in almost all lessons. Examples of factual errors, incorrectly asked questions, inaccurate images and pseudo-scientific simplifications are pointed.

scholarly journals Estimation of the mean normal measure from flat sections

2008 ◽  
Vol 40 (01) ◽  
pp. 31-48
Author(s):  
Markus Kiderlen
Keyword(s):  
A Priori ◽  
The Other ◽  
Consistent Estimator ◽  
Random Set ◽  
Normal Measure ◽  
Mild Assumption ◽  
The Mean ◽  
Vertical Sections ◽  
Almost All

We discuss the determination of the mean normal measure of a stationary random set Z ⊂ ℝ d by taking measurements at the intersections of Z with k-dimensional planes. We show that mean normal measures of sections with vertical planes determine the mean normal measure of Z if k ≥ 3 or if k = 2 and an additional mild assumption holds. The mean normal measures of finitely many flat sections are not sufficient for this purpose. On the other hand, a discrete mean normal measure can be verified (i.e. an a priori guess can be confirmed or discarded) using mean normal measures of intersections with m suitably chosen planes when m ≥ ⌊d / k⌋ + 1. This even holds for almost all m-tuples of k-dimensional planes are viable for verification. A consistent estimator for the mean normal measure of Z, based on stereological measurements in vertical sections, is also presented.

scholarly journals Cryptosystem using double vertex graph

2020 ◽  
Vol 13 (44) ◽  
pp. 4483-4489
Author(s):  
C Beaula ◽  
Keyword(s):  
Graph Theory ◽  
Secure Communication ◽  
System Method ◽  
Encryption And Decryption ◽  
Vertex Graph ◽  
Private And Public ◽  
Almost All ◽  
Encryption Method ◽  
The Given ◽  
Edge Labeling

Background/Objective: The Coronavirus Covid-19 has affected almost all the countries and millions of people got infected and more deaths have been reported everywhere. The uncertainty and fear created by the pandemic can be used by hackers to steal the data from both private and public systems. Hence, there is an urgent need to improve the security of the systems. This can be done only by building a strong cryptosystem. So many researchers started embedding different topics of mathematics like algebra, number theory, and so on in cryptography to keep the system, safe and secure. In this study, a cryptosystem using graph theory has been attempted, to strengthen the security of the system. Method: A new graph is constructed from the given graph, known as a double vertex graph. The edge labeling of this double vertex graph is used in encryption and decryption. Findings: A new cryptosystem using the amalgamation of the path, its double vertex graph and edge labeling has been proposed. From the double vertex graph of a path, we have given a method to find the original path. To hack such an encrypted key, the knowledge of graph theory is important, which makes the system stronger. Applications:The one-word encryption method will be useful in every security system that needs a password for secure communication or storage or authentication. Keywords: Double vertex graphs; path; adjacency matrix; encryption; cryptography

Pricing for Hill Tourism Destination

2019 ◽  
pp. 163-175
Author(s):  
Debasish Batabyal
Keyword(s):  
A Priori ◽  
Specific Model ◽  
Linear Regression Equation ◽  
Landscape Value ◽  
Capita Spending ◽  
Per Capita ◽  
Basic Characteristics ◽  
Almost All ◽  
Tangible Product ◽  
Tour Operator

Pricing an alpine tourism is unlike pricing a tangible product. As a part of overall marketing strategy pricing a destination has lot of intricate issues that starts from the basic characteristics of the destination elements to the changing demand aspects. At the time of packaging, an alpine destination by a tour operator or destination promotion organization (DPO), a simplified model, is used that is not essentially limited to an absurd analysis of attraction features through FAM trips a priori. In almost all Indian leisure destinations, tourists are found to be price sensitive and per capita spending is not so high. So, an Indian alpine destination-specific model, based on simple linear regression equation, largely explaining the spending of tourists and thereby implying a modified landscape value has been explained here.

A Context-Aware Model of Trust for Facilitating Secure Ad Hoc Collaborations

2010 ◽  
pp. 250-281 ◽  
Author(s):  
Indrajit Ray ◽  
Indrakshi Ray ◽  
Sudip Chakraborty
Keyword(s):  
Incomplete Information ◽  
Ad Hoc ◽  
Sensitive Information ◽  
Trust Value ◽  
Trust Relationships ◽  
The Face ◽  
Trust Models ◽  
Almost All ◽  
Ad Hoc Collaborations ◽  
The Given

Ad hoc collaborations often necessitate impromptu sharing of sensitive information or resources between member organizations. Each member of resulting collaboration needs to carefully assess and tradeoff the requirements of protecting its own sensitive information against the requirements of sharing some or all of them. The challenge is that no policies have been previously arrived at for such secure sharing (since the collaboration has been formed in an ad hoc manner). Thus, it needs to be done based on an evaluation of the trustworthiness of the recipient of the information or resources. In this chapter, the authors discuss some previously proposed trust models to determine if they can be effectively used to compute trustworthiness for such sharing purposes in ad hoc collaborations. Unfortunately, none of these models appear to be completely satisfactory. Almost all of them fail to satisfy one or more of the following requirements: (i) well defined techniques and procedures to evaluate and/or measure trust relationships, (ii) techniques to compare and compose trust values which are needed in the formation of collaborations, and (iii) techniques to evaluate trust in the face of incomplete information. This prompts the authors to propose a new vector (we use the term “vector” loosely; vector in this work means a tuple) model of trust that is suitable for reasoning about the trustworthiness of systems built from the integration of multiple subsystems, such as ad hoc collaborations. They identify three parameters on which trust depends and formulate how to evaluate trust relationships. The trust relationship between a truster and a trustee is associated with a context and depends on the experience, knowledge, and recommendation that the truster has with respect to the trustee in the given context. The authors show how their model can measure trust in a given context. Sometimes enough information is not available about a given context to calculate the trust value. Towards this end the authors show how the relationships between different contexts can be captured using a context graph. Formalizing the relationships between contexts allows us to extrapolate values from related contexts to approximate a trust value of an entity even when all the information needed to calculate the trust value is not available. Finally, the authors develop formalisms to compare two trust relationships and to compose two or more of the same – features that are invaluable in ad hoc collaborations.

scholarly journals Performance and Statistical Analysis of Stream ciphers in GSM Communications

2020 ◽  
Vol 16 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Nagendar Yerukala ◽  
V Kamakshi Prasad ◽  
Allam Apparao
Keyword(s):  
Statistical Analysis ◽  
Stream Cipher ◽  
Statistical Tests ◽  
Stream Ciphers ◽  
Test Suite ◽  
Secret Key ◽  
Initial State ◽  
Detailed Statistical Analysis ◽  
Almost All ◽  
The Given

For a stream cipher to be secure, the keystream generated by it should be uniformly random with parameter 1/2.Statistical tests check whether the given sequence follow a certain probability distribution. In this paper, we perform a detailed statistical analysis of various stream ciphers used in GSM 2G,3G, 4G and 5G communications. The sequences output by these ciphers are checked for randomness using the statistical tests defined by the NIST Test Suite. It should also be not possible to derive any information about secret key and the initial state ofthe cipher from the keystream. Therefore, additional statisticaltests based on properties like Correlation between Keystreamand Key, and Correlation between Keystream and IV are also performed. Performance analysis of the ciphers also has been done and the results tabulated. Almost all the ciphers pass thetests in the NIST test suite with 99% confidence level. For A5/3stream cipher, the correlation between the keystream and key is high and correlation between the keystream and IV is low when compared to other ciphers in the A5 family.

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