Yaşar University

About: Yaşar University is a education organization based out in Izmir, Turkey. It is known for research contribution in the topics: Exergy & Job shop scheduling. The organization has 760 authors who have published 1436 publications receiving 20813 citations. The organization is also known as: Yaşar Üniversitesi.

An artificial bee colony algorithm for the economic lot scheduling problem

Abstract: In this study, we present an artificial bee colony (ABC) algorithm for the economic lot scheduling problem modelled through the extended basic period (EBP) approach. We allow both power-of-two (PoT) and non-power-of-two multipliers in the solution representation. We develop mutation strategies to generate neighbouring food sources for the ABC algorithm and these strategies are also used to develop two different variable neighbourhood search algorithms to further enhance the solution quality. Our algorithm maintains both feasible and infeasible solutions in the population through the use of some sophisticated constraint handling methods. Experimental results show that the proposed algorithm succeeds to find the all the best-known EBP solutions for the high utilisation 10-item benchmark problems and improves the best known solutions for two of the six low utilisation 10-item benchmark problems. In addition, we develop a new problem instance with 50 items and run it at different utilisation levels ranging fr...

Hypoglycemic effect of crude exopolysaccharides produced by Cerrena unicolor, Coprinus comatus, and Lenzites betulina isolates in streptozotocin- induced diabetic rats

Abstract: The objective of this study was to investigate the hypoglycemic activity of crude exopolysaccharides (EPS) produced by three mushroom isolates in streptozotocin-induced diabetic rats. The three experimental groups were fed EPS of Cerrena unicolor (Bull.) Murrill (Polyporaceae), Coprinus comatus (O.F. Mull.) Pers. (Agaricaceae), and Lenzites betulina (L.) Fr. (Polyporaceae) for 7 days. The serum glucose levels significantly decreased after oral administration of EPS by 61.23% with Cerrena unicolor, 42.78% with Coprinus comatus, and 42.08% with Lenzites betulina. According to histological observations based on staining in pancreatic tissues, Langerhans islet areas and cell numbers of diabetic animals increased in response to EPS treatment. In conclusion, our findings clearly suggest that exopolysaccharides produced by three mushroom isolates decreased blood glucose levels in STZ-induced diabetic rats. Therefore, the studied mushroom exopolysaccharides might be developed as potential oral hypoglycemic agents...

How to (Pre-)Compute a Ladder

Abstract: In the RFC 7748 memorandum, the Internet Research Task Force specified a Montgomery-ladder scalar multiplication function based on two recently adopted elliptic curves, “curve25519” and “curve448”. The purpose of this function is to support the Diffie-Hellman key exchange algorithm that will be included in the forthcoming version of the Transport Layer Security cryptographic protocol. In this paper, we describe a ladder variant that permits to accelerate the fixed-point multiplication function inherent to the Diffie-Hellman key pair generation phase. Our proposal combines a right-to-left version of the Montgomery ladder along with the pre-computation of constant values directly derived from the base-point and its multiples. To our knowledge, this is the first proposal of a Montgomery ladder procedure for prime elliptic curves that admits the extensive use of pre-computation. In exchange of very modest memory resources and a small extra programming effort, the proposed ladder obtains significant speedups for software implementations. Moreover, our proposal fully complies with the RFC 7748 specification. A software implementation of the X25519 and X448 functions using our pre-computable ladder yields an acceleration factor of roughly 1.20, and 1.25 when implemented on the Haswell and the Skylake micro-architectures, respectively.

Faster Compact Diffie–Hellman: Endomorphisms on the x-line

Abstract: We describe an implementation of fast elliptic curve scalar multiplication, optimized for Diffie–Hellman Key Exchange at the 128-bit security level. The algorithms are compact (using only x-coordinates), run in constant time with uniform execution patterns, and do not distinguish between the curve and its quadratic twist; they thus have a built-in measure of side-channel resistance. (For comparison, we also implement two faster but non-constant-time algorithms.) The core of our construction is a suite of two-dimensional differential addition chains driven by efficient endomorphism decompositions, built on curves selected from a family of ℚ-curve reductions over \(\mathbb{F}_{p^2}\) with p = 2127 − 1. We include state-of-the-art experimental results for twist-secure, constant-time, x-coordinate-only scalar multiplication.