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.

Omitted variable bias and detection with reset test in regression analysis

Abstract: In this paper, it is aimed to investigate the omitted variable bias, its importance, reasons, and consequences and to research the methods for dealing with omitted variable bias and RESET test which is a method for detecting omitted variable(s). A simulation was performed and three types of populations which varied depending on the correlations between the variables were generated and random samples were drawn from these populations. When correlations were changed and the number of omitted variables was increased, the effects of omitted variable bias were investigated. Moreover, by increasing the sample size, it was investigated whether the effects of omitted variable bias were changed depending on sample size

Advances in model-based testing of graphical user interfaces

Abstract: Graphical user interfaces (GUIs) enable comfortable interactions of the computer-based systems with their environment. Large systems usually require complex GUIs, which are commonly fault prone and thus are to be carefully designed, implemented, and tested. As a thorough testing is not feasible, techniques are favored to test relevant features of the system under test that will be specifically modeled. This chapter summarizes, reviews, and exemplifies conventional and novel techniques for model-based GUI testing.

Yeni bir depo tasarım problemi ve polinomsal zamanlı optimal sipariş toplama algoritması önerisi

Abstract: Bu calismada, depolardaki ana koridorlarin yerlesim duzeni ile ilgili olarak yeni bir tasarim problemi tanimlanmistir. Bu problemde, depolarda siklikla kullanilan dogrusal duz orta ana koridor kesikli olarak, ornegin mal toplama koridorlari uzerindeki tuneller olarak tanimlanmistir. Boylece, depolarda en maliyetli ve siparis teslim suresini en cok etkileyen islemlerden birisi olan siparis toplama islemini daha etkin hale getirebilmek icin tunellerin nerelere konumlandirilacagi problemi ortaya atilmistir. Ayrica, bu yeni tasarim probleminde siparis toplama rota uzunlugunu optimal olarak hesaplayabilmek icin polinomsal zamanda dinamik programlama esasli yeni bir algoritma gelistirilmistir. Gelistirilen bu algoritma ile buyuk sayidaki siparisler icin bile cok kisa surede sonuclar alinmistir. Gelistirilen algoritmanin performansi literaturde gezgin satici probleminin cozumunde kullanilan Held-Karp dal-sinir algoritmasi ile karsilastirilmistir. Son olarak, ornek bir problem cozulmus ve algoritmanin uygulanmasi anlatilmistir.

Energy efficient automated warehouse design

Abstract: The aim of this work is to study an automated warehousing system design to optimize significant performance metrics: energy and travel time related performance metrics in the system. Different from the literature, we study a specific design of a well-known automated warehousing system, shuttle-based storage and retrieval system (SBS/RS), in which shuttles can travel between tiers by using a lifting mechanism installed at periphery of racks. In a traditional SBS/RS design, shuttles are dedicated in each tier that is tier-captive. They perform horizontal travel for storage and retrieval of loads within a tier of an aisle. There is a single lifting mechanism in each aisle for vertical travel of loads. These systems are mostly utilized in large distribution centers to obtain high transaction rate for storage and retrieval processes. In a traditional design, because there is a dedicated shuttle in each tier of an aisle and a single lifting mechanism in each aisle, lifts are mostly bottleneck and the utilization of shuttles are very low. Hence, a new design with a few numbers of shuttles that can travel between tiers might be promising in decreasing the initial investment cost and increasing the utilization levels of shuttles. In this work, we explore an optimal warehouse design for that new SBS/RS concept—tier-to-tier SBS/RS—in terms of number of shuttles, number of tiers, aisles, acceleration/deceleration values of lifts/shuttles, etc. to improve some significant performance metrics from the system (e.g., energy consumption and cycle time per transaction).