This paper studies the descriptional complexity of multi-parallel grammars with respect to the number of nonterminals and selectors, and the length of these selectors. As a result, it proves that every recursively enumerable language is generated by a multi-parallel grammar with no more than seven nonterminals and four selectors of length five.

Protection of privacy in databases has become of increasing importance. While a number of techniques have been proposed to query databases while preserving privacy of individual records in the database, very little is done to define a measure on how much privacy is lost after statistical releases. We suggest a definition based on information theory. Intuitively, the privacy loss is proportional...

Posttraumatic growth (PTG) is a person’s mental experience of positive psychological changes induced by encountering extremely challenging situations. This study aimed to investigate the concept of posttraumatic growth and its relationship with quality of life (QOL) in cancer patients. This is a descriptive cross-sectional study. The study population consisted of cancer patients referred to two...

let r be an associative ring with identity, c(r) be the category of com-plexes of r-modules and flat(c(r)) be the class of all at complexes of r-modules. we show that the at cotorsion theory (flat(c(r)); flat(c(r))−)have enough injectives in c(r). as an application, we prove that for each atcomplex f and each complex y of r-modules, exti (f,x)= 0, whenever ris n-perfect and i > n.

BACKGROUND Human rights violations are commonly reported against people with mental illness and have remained a major research issue in recent times. OBJECTIVE The present study was aimed to compare psychiatric patients' perceptions of human rights needs between rural and urban settings. METHODOLOGY A descriptive study design was carried out among 100 recovered psychiatric patients based on...

introduction: intellectual capitals in an organization are assets that their value is increased over time and with sharing with others. since hospitals are dominant in providing medical services, management of intangible assets could be very important for them. to avoid the waste of costs and efforts, it is necessary to identify the priority and importance of each dimension of intellectual capi...

Weakly recognizing morphisms from free semigroups onto finite semigroups are a classical way for defining the class of ω-regular languages, i.e., a set of infinite words is weakly recognizable by such a morphism if and only if it is accepted by some Büchi automaton. We consider the descriptional complexity of various constructions for weakly recognizing morphisms. This includes the conversion f...