Trace formulas for Schrödinger operators on star graphs

We derive trace formulas of the Buslaev–Faddeev type for quantum star graphs. One of the new ingredients is high energy asymptotics of the perturbation determinant

Application of Activity Based Costing in Reverse Logistics Environment: A Case of End-of-life Vehicle Recovery in Turkey

Nowadays, there has been a growing interest in reverse logistics in both theory and practice due to legislations, economic and ecological benefits, and social responsibilities. If enterprises incorporating reverse logistics activities to its structure want to realize the required level of customer service and comply with related obligations at the lowest total cost, analyzing the actualized reverse logistics activities and correct determination and reduction of costs of these activities are essential for them. Traditional accounting methods are inadequate for accurate assignment of overhead costs. In this paper, an actual application of Activity Based Costing (ABC) to reverse logistics activities is presented in order to help managers to improve their understanding of costs that arises from reverse logistics activities. An illustrative case study in the end-of-life vehicle (ELV) recovery industry in Turkey is presented to demonstrate the steps of how ABC is applied to reverse logistics systems. The results enable to efficient management of reverse logistics activities and their costs in an ELV recovery chain and exhibit which reverse logistics activities performed by a dismantler cause the highest cost and can be improved. In the case study, products (ELVs) are evaluated as inputs and the obtained materials from reverse logistics activities are evaluated as outputs of the system by force of the nature of reverse logistics. Results show that while most cost of the company (52.7%) was related with the output of B Group of components/parts (sent to shredders); the minimum cost (12.3%) was realized for the output of A Group components/parts (sent to recyclers). The remaining 35% of the costs belong to the C Group of outputs (sent to secondary markets)

The spectral shift function and Levinson's theorem for quantum star graphs

We consider the Schr\"odinger operator on a star shaped graph with $n$ edges joined at a single vertex. We derive an expression for the trace of the difference of the perturbed and unperturbed resolvent in terms of a Wronskian. This leads to representations for the perturbation determinant and the spectral shift function, and to an analog of Levinson's formula

Spectral Inequalities for Quantum Graphs

We review our joint work with Evans Harrell on semiclassical and universal inequalities for quantum graphs. The proofs of these inequalities are based on an abstract trace inequality for commutators of operators. In this article we give a new proof of this abstract trace inequality. Another ingredient in proving semiclassical and universal inequalities is an appropriate choice of operators in this trace inequality. We provide a new approximation method for such a choice

ADAPTATION OF THE ATTITUDE TOWARD SUSTAINABLE DEVELOPMENT SCALE TO TURKISH

This study aimed to adapt the Attitudes toward Sustainable Development Scale (ASDS) to Turkish. To this end, the ASDS, which has 20 items in the dimensions of environment, economy, society, and education, was translated into Turkish and piloted in a group of 205 pre-service science teachers. Two items were revised based on the preliminary findings of the pilot study. Then, the revised instrument was administered to 281 pre-service science teachers. Confirmatory factor analysis results supported the 4-factor structure. Convergent and discriminant validity evidence was also obtained for the Turkish version of the ASDS. Additionally, reliability analyses suggested high internal consistency. The results related to the measurement invariance across gender showed that the data from both male and female pre-service science teachers lead to equally valid conclusions concerning attitude toward sustainable development. Overall, the findings suggested that Turkish version of the Attitudes toward Sustainable Development Scale can be utilized as a valid and reliable instrument to measure and understand the pre-service science teachers’ attitudes toward sustainable development.</p