scholarly journals Multilevel Diversity Coding with Secure Regeneration: Separate Coding Achieves the MBR Point

Entropy ◽  
2018 ◽  
Vol 20 (10) ◽  
pp. 751
Author(s):  
Shuo Shao ◽  
Tie Liu ◽  
Chao Tian ◽  
Cong Shen
Keyword(s):  
Storage Capacity ◽  
Trade Off ◽  
The Core ◽  
Diversity Coding ◽  
Special Cases ◽  
Minimum Bandwidth ◽  
Regenerating Code ◽  
Outer Bounds ◽  
Converse Results

The problem of multilevel diversity coding with secure regeneration (MDC-SR) is considered, which includes the problems of multilevel diversity coding with regeneration (MDC-R) and secure regenerating code (SRC) as special cases. Two outer bounds are established, showing that separate coding can achieve the minimum-bandwidth-regeneration (MBR) point of the achievable normalized storage-capacity repair-bandwidth trade-off regions for the general MDC-SR problem. The core of the new converse results is an exchange lemma, which can be established using Han’s subset inequality.

Computing Cores for Existential Rules with the Standard Chase and ASP

2020 ◽  
Author(s):  
Markus Krötzsch
Keyword(s):  
Large Class ◽  
Data Exchange ◽  
Answer Set Programming ◽  
Query Answering ◽  
Universal Model ◽  
The Core ◽  
Universal Models ◽  
General Terms ◽  
Special Cases ◽  
The Many

To reason with existential rules (a.k.a. tuple-generating dependencies), one often computes universal models. Among the many such models of different structure and cardinality, the core is arguably the “best”. Especially for finitely satisfiable theories, where the core is the unique smallest universal model, it has advantages in query answering, non-monotonic reasoning, and data exchange. Unfortunately, computing cores is difficult and not supported by most reasoners. We therefore propose ways of computing cores using practically implemented methods from rule reasoning and answer set programming. Our focus is on cases where the standard chase algorithm produces a core. We characterise this desirable situation in general terms that apply to a large class of cores, derive concrete approaches for decidable special cases, and generalise these approaches to non-monotonic extensions of existential rules.

Analysis of Advanced PWR Loading Schemes for Transuranic Incineration in Thorium

2013 ◽  
Author(s):  
Benjamin A. Lindley ◽  
N. Zara Zainuddin ◽  
Fausto Franceschini ◽  
Geoffrey T. Parks
Keyword(s):  
Temperature Coefficient ◽  
Preliminary Analysis ◽  
Detrimental Effect ◽  
Spatial Separation ◽  
Trade Off ◽  
The Core ◽  
Positive Reactivity ◽  
Fuel Pin ◽  
Control Rods

It is difficult to perform multiple recycle of transuranic (TRU) isotopes in PWRs as the moderator temperature coefficient (MTC) tends to become positive after a few recycles and the core may have positive reactivity when fully voided. Due to the favorable impact on the MTC and void coefficient fostered by use of thorium (Th), the possibility of performing Th-TRU multiple-recycle in reduced-moderation PWRs (RMPWRs) is under consideration. The simplest way to reduce the moderation in a PWR is to increase the fuel pin diameter. This configuration improves the trade-off between achievable burn-up and MTC, but is ultimately limited by thermal-hydraulic constraints. Heterogeneous recycle with the bred uranium (U3) and the TRU are arranged in separate pins was found to be neutronically preferable to a homogeneous configuration. Spatial separation also enables the U3 and TRU to be refueled on different batch schemes. These techniques allow satisfactory discharge burn-up while ensuring negative MTC and fully voided reactivity, with the pin diameter of a standard PWR increased from 9.5 mm to 11 mm. Reactivity control is a key challenge due to the reduced worth of neutron absorbers and their detrimental effect on the void coefficients, especially when diluted, as is the case for soluble boron. It seems necessary to control the core using control rods to keep the fully voided reactivity negative. A preliminary analysis indicates that this is feasible.

ON TWO THEOREMS OF QUINZII AND RENT CONTROLLED HOUSING ALLOCATION IN SWEDEN

2007 ◽  
Vol 09 (03) ◽  
pp. 515-525
Author(s):  
KIMMO ERIKSSON ◽  
JONAS SJÖSTRAND
Keyword(s):  
Control System ◽  
Empirical Data ◽  
General Theorem ◽  
Black Market ◽  
Utility Functions ◽  
Rent Control ◽  
Black And White ◽  
The Core ◽  
Special Cases ◽  
Housing Allocation

The Swedish rent control system creates a white market for swapping rental contracts and a black market for selling rental contracts. Empirical data suggests that in this black-and-white market some people act according to utility functions that are both discontinuous and locally decreasing in money. We discuss Quinzii's theorem for the nonemptiness of the core of generalized house-swapping games, and show how it can be extended to cover the Swedish game. In a second part, we show how this theorem of Quinzii and her second theorem on nonemptiness of the core in two-sided models are both special cases of a more general theorem.

scholarly journals Probability of infectious disease in humans during epidemic

2021 ◽  
Author(s):  
AM Karmishin ◽  
IV Borisevich ◽  
VI Skvortsova ◽  
AA Goryaev ◽  
SM Yudin
Keyword(s):  
Infectious Disease ◽  
Biological Object ◽  
Epidemiological Modeling ◽  
Pathogen Virulence ◽  
The Core ◽  
Special Cases ◽  
Quantitative Characteristics ◽  
Infective Dose ◽  
The Law ◽  
Generalized Time

Popular SIR models and their modifications used to generate predictions about epidemics and, specifically, the COVID-19 pandemic, are inadequate. The aim of this study was to find the laws describing the probability of infection in a biological object. Using theoretical methods of research based on the probability theory, we constructed the laws describing the probability of infection in a human depending on the infective dose and considering the temporal characteristics of a given infection. The so-called generalized time-factor law, which factors in the time of onset and the duration of an infectious disease, was found to be the most general. Among its special cases are the law describing the probability of infection developing by some point in time t, depending on the infective dose, and the law that does not factor in the time of onset. The study produced a full list of quantitative characteristics of pathogen virulence. The laws described in the study help to solve practical tasks and should lie at the core of mathematical epidemiological modeling.

scholarly journals Inbreeding parents should invest more resources in fewer offspring

2016 ◽  
Author(s):  
A. Bradley Duthie ◽  
Aline M. Lee ◽  
Jane M. Reid
Keyword(s):  
General Theory ◽  
Evolutionary Dynamics ◽  
Inbreeding Avoidance ◽  
The Other ◽  
Trade Off ◽  
Offspring Number ◽  
Focal Female ◽  
Special Cases ◽  
Selection For ◽  
Joint Consideration

AbstractInbreeding increases parent-offspring relatedness and commonly reduces offspring viability, shaping selection on reproductive interactions involving relatives and associated parental investment (PI). Nevertheless, theories predicting selection for inbreeding versus inbreeding avoidance and selection for optimal PI have only been considered separately, precluding prediction of optimal PI and associated reproductive strategy given inbreeding. We unify inbreeding and PI theory, demonstrating that optimal PI increases when a female's inbreeding decreases the viability of her offspring. Inbreeding females should therefore produce fewer offspring due to the fundamental trade-off between offspring number and PI. Accordingly, selection for inbreeding versus inbreeding avoidance changes when females can adjust PI with the degree that they inbreed. In contrast, optimal PI does not depend on whether a focal female is herself inbred. However, inbreeding causes optimal PI to increase given strict monogamy and associated biparental investment compared to female-only investment. Our model implies that understanding evolutionary dynamics of inbreeding strategy, inbreeding depression, and PI requires joint consideration of the expression of each in relation to the other. Overall, we demonstrate that existing PI and inbreeding theories represent special cases of a more general theory, implying that intrinsic links between inbreeding and PI affect evolution of behaviour and intra-familial conflict.

Effect of Cell Geometry on the Shear Modulus and on Density of Sandwich Panel Cores

1961 ◽  
Vol 83 (4) ◽  
pp. 513-517 ◽  
Author(s):  
Chieh C. Chang ◽  
Ibrahim K. Ebcioglu
Keyword(s):  
Aspect Ratio ◽  
Shear Modulus ◽  
Sandwich Panel ◽  
Analytic Theory ◽  
Cell Geometry ◽  
Cell Weight ◽  
The Core ◽  
Special Cases ◽  
Square Cells ◽  
Sandwich Core

A simple analytic theory for the effect of cell geometry on both the shear modulus and the density of sandwich panel core is presented. The core shear modulus in different directions is analyzed to include the effects of the angle α and the aspect ratio b/a of the cell. It is also found that the minimum cell weight of the sandwich core depends both on the cell angle α and the cell aspect ratio b/a. The theory compares fairly well with some available experiments. The cell geometry chosen is so general that the regular hexagonal and square cells of commercial sandwich cores are special cases.

Prompting additional purchases while providing service: does it offend the customer?

2016 ◽  
Vol 26 (5) ◽  
pp. 657-680 ◽  
Author(s):  
Hsuan-Hsuan Ku ◽  
Chih-Yun Huang
Keyword(s):  
Design Methodology ◽  
Psychological Reactance ◽  
Self Monitoring ◽  
Trade Off ◽  
Content Type ◽  
The Core ◽  
Personal Variables ◽  
Core Service ◽  
Perceived Relevance ◽  
Supplementary Service

Purpose The purpose of this paper is to investigate consumers’ responses to unsolicited cross-selling of supplementary paid-for services made during delivery of a core service, and the contextual and personal variables moderating those responses. Design/methodology/approach Three formal experiments test the effect on participants’ responses of the perceived relevance of the supplementary service to the core service, personal psychological reactance, in the case of a high-relevance supplementary service, and self-monitoring, in scenarios in which a low-relevance supplementary service is proposed either in public or privately. Findings The experiments found that participants’ satisfaction ratings were reduced in response to cross-selling of a supplementary service that was of low relevance to the core service, and that satisfaction ratings if it was perceived to be of high relevance compared were not reduced despite the unsolicited attempt at cross-selling. However, the non-negative response to a high-relevance offer was limited to participants with a lower tendency to reactance. Furthermore, a high predisposition to self-monitoring evoked more positive judgments if a low-relevance supplementary service was proposed in public rather than privately. That of low self-monitors was no different in either case. Originality/value This paper examines the trade-off faced by a service provider between customer satisfaction and extra revenue from supplementary services, and explores conditions under which a provider can propose unsolicited supplementary services without offending customers.

THE CORE AND CONSISTENCY PROPERTIES: A GENERAL CHARACTERISATION

2001 ◽  
Vol 03 (02n03) ◽  
pp. 175-187 ◽  
Author(s):  
YUKIHIKO FUNAKI ◽  
TAKEHIKO YAMATO
Keyword(s):  
General Theorem ◽  
General Definition ◽  
Tu Games ◽  
The Core ◽  
Special Cases ◽  
Reduced Games ◽  
Definition Of ◽  
Consistency Properties

In this paper, we unify various axiomatisations of the core of TU games by means of consistency with respect to different definitions of reduced games. First, we introduce a general definition of reduced games including the reduced games due to Davis and Maschler (1965), Moulin (1985), and Funaki (1995) as special cases. Then, we provide a general theorem from which the characterisations due to Peleg (1986), Tadenuma (1992), and Funaki (1995) can be obtained. Our general theorem clarifies how the three characterisations of the core differ and are related.

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