Bahar Sennaroglu

An evolutionary multi-objective optimization approach to disaster waste management

A framework to determine the locations of temporary storage sites is proposed.A sustainable solution methodology for disaster waste management is provided.The framework not only considers the cost but also the side effects on human beings.Utilization of debris is a gap in research and this study aims to fill this gap.This is the only study using NSGA-II to solve debris utilization problem. Disasters can lead to a high risk of casualties and structural damages. Destructive disasters, such as earthquakes, may cause a great amount of disaster waste to be controlled. Reusing and recycling materials in the debris can decrease the need for re-construction resources. These reusable or recyclable materials can be processed in temporary storage sites like the ones suggested by the United Nations and the United States Federal Emergency Management Agency guidelines on disaster waste management. The objective of this paper is to build a framework for determining the locations of temporary storage facilities, and includes planning for the collection and transportation of disaster waste in order to manage it in an environmentally sustainable way. In this study, a multi-objective optimization model is developed and solved with an evolutionary elitist multi-objective optimization algorithm (NSGA-II). As a city prone to high earthquake damage, Istanbul has been selected for the illustration of the proposed framework. The objectives of the model are cost minimization and minimization of risk from hazardous waste exposure. The study integrates disaster loss estimation methods with post-disaster waste management.

Self-Consolidating High-Strength Concrete Optimization by Mixture Design Method

This article will review how the demand for the combination of high-strength concrete (HSC) and self-consolidating concrete (SCC) placeability has been growing worldwide. Concrete mixture proportions for HSC and SCC have varied widely depending on many factors and sensitive interactions between components. In practice, many trial batches are often required to generate the data that enable identification of optimum mixture proportions. Statistical mixture design (SMD) methods based on experiments constitute a new application area and prove to be a useful tool in terms of providing cost-effective means of the concrete optimization. In this study, the self-consolidating HSC in the C100/115 concrete class was optimized using D-optimal design, which is the most popular because of its simple computation and because there were constraints on the eight mixture component proportions. Test results from 46 experimental runs were analyzed to reach an optimum mixture proportion. SMD methods provide a methodical scientific solution to what has, up until now, been a trial-and-error process.

A combined decision model for R&D project portfolio selection

In this paper, a combined decision model for selecting and prioritising Research and Development (Ramp;D) projects is proposed. The aim of this study is to provide a systematic approach for project portfolio selection. Analytic Hierarchy Process (AHP), Data Envelopment Analysis (DEA) and Value Tree Analysis (VTA) are implemented and combined in the proposed model to determine the efficient and feasible projects among the alternative RAmp;D projects. The proposed model utilises both quantitative and qualitative information for project portfolio selection. The efficient projects with the higher feasibility scores have the higher priority over the alternative R&D projects. Decision-makers of R&D projects can use the proposed model to select the right projects, which are efficient and feasible using both quantitative and qualitative information available.

Sintering Effect on Mechanical Properties of Composites of Hydroxyapatite Lanthanum Oxide (HA-La2O3)

Composites of calcinated bovine bone derived hydroxyapatite (HA) with 0.25, 0.5, 1, and 2 wt % La2O3 were prepared by sintering. The experimental results indicated that compression strength and microhardness of HA-La2O3 composites increase when the content of La2O3 and sintering temperature increase. The best mechanical properties were achieved after sintering at 1300°C. The results are in agreement with densification measurements and microstructure analysis.

A comparative study of production control systems through simulation

The purpose of this paper is to simulate pull, push and hybrid production control systems for a single line, multi-stage and continuous production process, which is aluminium casting, in order to compare their performances where the current production control system is push system. The paper also provides an approach in constructing hybrid system by using TSP in minimizing total setup time to obtain optimal sequence of orders.

Influence of Sintering Temperature on Mechanical Properties of Biologically Derived Hydroxyapatite Bodies

The properties of sintered hydroxyapatite (HA), obtained from bovine femoral shafts via calcination method, were investigated utilizing scanning electron microscopy (SEM) and X-ray diffraction analysis together with measurements of microhardness, density, and compression strength. The production of HA from natural sources is preferred due to money and time saving reasons. The results indicate the new HA materials as promissing in biomedicine, since similar mechanical behaviour was obtained with previous studies.

Association rules in innovative technology collaboration

SMEs are motivated to collaborate for research and innovation in order to survive in global competition. Recent studies showed that using advanced communication and information technologies will improve innovative collaboration among the SMEs. In competitive environment, technology based SMEs need to constitute successful collaborations for sustainability. Randomly chosen collaborators have shown failures that caused the fear to become an obstacle. Failures are mainly faced by the lack of innovation culture and the wrong collaboration type. Technoparks are the main field of research of high technology business catalyzing the innovation. Different units in technoparks may emerge perceptible competences, and productive businesses. Most effective players of regional innovation are innovation stimulating institutions. This study aims to define and validate the association rules for success for collaborations in the techno parks. A survey is run on more than 110 SMEs in 4 techno parks of Turkey. Statistical analysis and machine learning methods are applied to define the association rules for success. Rules achieved by applying the logistic regression are cross validated with the rules detected by applying support vector machine. The validated collaboration rules extracted as a result of the study will support strategic decisions for innovative technology collaboration.

Clustering of small and medium-sized enterprises as a strategy for their competitiveness

Economies in the world are supporting small and medium-sized enterprises (SMEs) due to increasing unemployment rates. But increasing costs of inputs for production of goods and services are barriers to competitiveness and growth of SMEs. Clustering of SMEs is an appropriate strategy to overcome these limitations, since it enables to reduce costs of inputs through collaborative contracts with suppliers and gain competitive advantages in the marketplace. Although it is an appropriate strategy, clustering is a difficult process for SMEs. This paper explains competitive advantages of clustering of SMEs and describes a clustering process for procurement. Clustering makes it possible for SMEs to benefit from economies of scale and high quality levels available to large enterprises, and hence achieve sustainable competitiveness. Sustainable competitiveness of SMEs is the key to their growth and their investments in technology and R&D.