24 research outputs found
The output estimation of a DMU to preserve and improvement of the relative efficiency
In this paper, we consider the inverse BCC model is used to estimate output levels of the Decision Making Units (DMUs), when the input levels are changed and maintain the efficiency index for all DMUs. Since the inverse BCC problem is in the form of a multi objective nonlinear programming model (MONLP), which is not easy to solve. Therefore, we propose a linear programming model, which gives a Pareto-efficient solution to the inverse BCC problem. So far, we propose a model for improvement of the current efficiency value for considered DMU. Numerical examples are, also, used to illustrate the proposed approaches
On the Capacity Region for Secure Index Coding
We study the index coding problem in the presence of an eavesdropper, where
the aim is to communicate without allowing the eavesdropper to learn any single
message aside from the messages it may already know as side information. We
establish an outer bound on the underlying secure capacity region of the index
coding problem, which includes polymatroidal and security constraints, as well
as the set of additional decoding constraints for legitimate receivers. We then
propose a secure variant of the composite coding scheme, which yields an inner
bound on the secure capacity region of the index coding problem. For the
achievability of secure composite coding, a secret key with vanishingly small
rate may be needed to ensure that each legitimate receiver who wants the same
message as the eavesdropper, knows at least two more messages than the
eavesdropper. For all securely feasible index coding problems with four or
fewer messages, our numerical results establish the secure index coding
capacity region
Improved Lower Bounds for Pliable Index Coding using Absent Receivers
This paper studies pliable index coding, in which a sender broadcasts
information to multiple receivers through a shared broadcast medium, and the
receivers each have some message a priori and want any message they do not
have. An approach, based on receivers that are absent from the problem, was
previously proposed to find lower bounds on the optimal broadcast rate. In this
paper, we introduce new techniques to obtained better lower bounds, and derive
the optimal broadcast rates for new classes of the problems, including all
problems with up to four absent receivers.Comment: An extended version of the same-titled paper submitted to a
conferenc
Multi-criteria decision analysis with goal programming in engineering, management and social sciences: a state-of-the art review
Preferential Pliable Index Coding
We propose and study a variant of pliable index coding (PICOD) where
receivers have preferences for their unknown messages and give each unknown
message a preference ranking. We call this the preferential pliable
index-coding (PPICOD) problem and study the Pareto trade-off between the code
length and overall satisfaction metric among all receivers. We derive
theoretical characteristics of the PPICOD problem in terms of interactions
between achievable code length and satisfaction metric. We also conceptually
characterise two methods for computation of the Pareto boundary of the set of
all achievable code length-satisfaction pairs. As for a coding scheme, we
extend the Greedy Cover Algorithm for PICOD by Brahma and Fragouli, 2015, to
balance the number of satisfied receivers and average satisfaction metric in
each iteration. We present numerical results which show the efficacy of our
proposed algorithm in approaching the Pareto boundary, found via brute-force
computation.Comment: An extended version of the same-titled paper accepted for
presentation at the 2023 IEEE International Symposium on Information Theory
(ISIT
On the capacity region for secure index coding
We study the index coding problem in the presence of an eavesdropper, where the aim is to communicate without allowing the eavesdropper to learn any single message aside from the messages it may already know as side information. We establish an outer bound on the underlying secure capacity region of the index coding problem, which includes polymatroidal and security constraints, as well as the set of additional decoding constraints for legitimate receivers. We then propose a secure variant of the composite coding scheme, which yields an inner bound on the secure capacity region of the index coding problem. For the achievability of secure composite coding, a secret key with vanishingly small rate may be needed to ensure that each legitimate receiver who wants the same message as the eavesdropper, knows at least two more messages than the eavesdropper. For all securely feasible index coding problems with four or fewer messages, our numerical results establish the secure index coding capacity region
Causal attributions and executive functions of academic procrastination in Mansoura University students
Lifestyle risk factor assessment through who step approach in Tabriz, Iran
Background: The aim of this study was to assess the lifestyle behaviour and risk factors for lifestyle-related diseases in East Azerbaijan province, Iran. Methods: A household study using a two-stage cluster sampling method was performed. Tabriz city was randomly selected for data collection among five geographic regions in the East-Azerbaijan province. Short WHO-STEP and Ultra-short version of Socio-Economic Status assessment questionnaire were used. Six hundred households were asked to respond to the STEP questionnaire. Results: A total of 1196 people have participated in the study. People with higher socioeconomic status consumed more fruits, vegetables and fish than the people with lower socioeconomic status. People with academic education less likely to be hypertensive com-pared to people with non-academic education. People with a medium socioeconomic status are less likely to be hypertensive than people with high socioeconomic status. The majority of participants had poor dietary habits. In this study, 17.22%, 7.53% and 4.35% of respon-dents had hypertension, diabetes and depression, respectively. Conclusion: Considering that lifestyle-related risk factors are common among people. Due to the direct link between lifestyle and the occurrence of many chronic diseases, campaigns for and training programs to implement healthy lifestyle habits are recommended.