Showing papers by "Yaşar University published in 2018"

Many Labs 2: Investigating Variation in Replicability Across Samples and Settings

Abstract: We conducted preregistered replications of 28 classic and contemporary published findings, with protocols that were peer reviewed in advance, to examine variation in effect magnitudes across samples and settings. Each protocol was administered to approximately half of 125 samples that comprised 15,305 participants from 36 countries and territories. Using the conventional criterion of statistical significance (p < .05), we found that 15 (54%) of the replications provided evidence of a statistically significant effect in the same direction as the original finding. With a strict significance criterion (p < .0001), 14 (50%) of the replications still provided such evidence, a reflection of the extremely high-powered design. Seven (25%) of the replications yielded effect sizes larger than the original ones, and 21 (75%) yielded effect sizes smaller than the original ones. The median comparable Cohen’s ds were 0.60 for the original findings and 0.15 for the replications. The effect sizes were small (< 0.20) in 16 of the replications (57%), and 9 effects (32%) were in the direction opposite the direction of the original effect. Across settings, the Q statistic indicated significant heterogeneity in 11 (39%) of the replication effects, and most of those were among the findings with the largest overall effect sizes; only 1 effect that was near zero in the aggregate showed significant heterogeneity according to this measure. Only 1 effect had a tau value greater than .20, an indication of moderate heterogeneity. Eight others had tau values near or slightly above .10, an indication of slight heterogeneity. Moderation tests indicated that very little heterogeneity was attributable to the order in which the tasks were performed or whether the tasks were administered in lab versus online. Exploratory comparisons revealed little heterogeneity between Western, educated, industrialized, rich, and democratic (WEIRD) cultures and less WEIRD cultures (i.e., cultures with relatively high and low WEIRDness scores, respectively). Cumulatively, variability in the observed effect sizes was attributable more to the effect being studied than to the sample or setting in which it was studied.

Minimizing losses in milk supply chain with sustainability: An example from an emerging economy

Abstract: Food loss in supply chain is a growing problem due to its environmental, social and economic impacts. Especially in emerging economies losses mostly occur in the first stages of the supply chain including agricultural production and postharvest storage. As an emerging economy, Turkey, also suffers from the food losses in the supply chain. In this study, focus is on raw milk losses in the supply chain since livestock and diary sectors are one of the most important sectors in Turkey’s economy. Aim of this study is firstly, to investigate root causes of raw milk losses in the supply chain and to predict potential raw milk losses. Secondly, presenting a sustainable solution according to the results of the prediction and finally achieving environmental, social and economic benefits for sustainable raw milk supply chain. Grey Method is used to predict potential losses between 2017–2019 and at the end of the study, triple bottom line based sustainable collection center model is suggested for policymakers.

Frontoparietal tDCS Benefits Visual Working Memory in Older Adults With Low Working Memory Capacity.

Abstract: Working memory (WM) permits maintenance of information over brief delays and is an essential executive function. Unfortunately, WM is subject to age-related decline. Some evidence supports the use of transcranial direct current stimulation (tDCS) to improve visual WM. A gap in knowledge is an understanding of the mechanism characterizing these tDCS linked effects. To address this gap, we compared the effects of two tDCS montages designed on visual working memory (VWM) performance. The bifrontal montage was designed to stimulate the heightened bilateral frontal activity observed in aging adults. The unilateral frontoparietal montage was designed to stimulate activation patterns observed in young adults. Participants completed three sessions (bilateral frontal, right frontoparietal, sham) of anodal tDCS (20 min, 2 mA). During stimulation, participants performed a visual long-term memory (LTM) control task and a visual WM task. There was no effect of tDCS on the LTM task. Participants receiving right unilateral tDCS showed a WM benefit. This pattern was most robust in older adults with low WM capacity. To address the concern that the key difference between the two tDCS montages could be tDCS over the posterior parietal cortex (PPC), we included new analyses from a previous study applying tDCS targeting the PPC paired with a recognition VWM task. No significant main effects were found. A subsequent experiment in young adults found no significant effect of either tDCS montage on either task. These data indicate that tDCS montage, age and WM capacity should be considered when designing tDCS protocols. We interpret these findings as suggestive that protocols designed to restore more youthful patterns of brain activity are superior to those that compensate for age-related changes.

Evaluating Reliability/Survivability of Capacitated Wireless Networks

Abstract: In telecommunication network design problems, survivability and reliability are often used to evaluate quality of service while usually ignoring link capacity. In this paper, a new metric that combines network reliability with network resilience is presented to measure reliability/survivability effectively for capacitated networks. Capacitated resilience is compared with well-known network reliability/survivability metrics ( $k$ -terminal reliability, all-terminal reliability, traffic efficiency, and $k$ -connectivity), and its benefits and computational efficiency are discussed. An application is shown using heterogeneous wireless networks (HetNets). With the growing use of new telecommunication technologies such as 4G and wireless hotspots, HetNets are gaining more attention. The source of heterogeneity of a HetNet can either be the differences in nodes (such as transmission ranges, failure rates, and energy levels) or the differences in services offered in the network (such as GSM and WiFi).

Hierarchical Electric Vehicle Charging Aggregator Strategy Using Dantzig-Wolfe Decomposition

Abstract: This article focuses on reducing a charging cost for electric vehicles (EVs). A charging strategy is proposed to minimize the charging cost of EVs within the charging station constraints. —Zili Shao

Exploring dimensions of slow tourism motivation

Abstract: Today, the tourism industry has altered from a steady structure to a dynamic one in order to match the emerging needs, wants and demands of tourists. Given this, understanding the motivations of tourists is key to designing better products and services. Motivation is closely linked to satisfaction, and is a crucial ingredient in terms of understanding visitors’ decision-making processes. Thus, destination marketers need to understand what motivates people to choose slow tourism, as well what segments are interested in that specific type of tourism. Examining slow tourists, this study identified seven tourist motivation factors thereof. In terms of push factors, “Relaxation”, “Self-reflection & Discovery”, “Escape”, “Novelty-seeking”, “Environmental Concern” and “Social Interaction” were identified, along with “Engagement” as a pull factor.

Constraint and Mathematical Programming Models for Integrated Port Container Terminal Operations

Abstract: This paper considers the integrated problem of quay crane assignment, quay crane scheduling, yard location assignment, and vehicle dispatching operations at a container terminal. The main objective is to minimize vessel turnover times and maximize the terminal throughput, which are key economic drivers in terminal operations. Due to their computational complexities, these problems are not optimized jointly in existing work. This paper revisits this limitation and proposes Mixed Integer Programming (MIP) and Constraint Programming (CP) models for the integrated problem, under some realistic assumptions. Experimental results show that the MIP formulation can only solve small instances, while the CP model finds optimal solutions in reasonable times for realistic instances derived from actual container terminal operations.

Distribution of strong earthquake input energy in tall buildings equipped with damped outriggers

Abstract: The seismic design of optimal damped outrigger structures relies on the assumption that most of the input energy will be absorbed by the dampers, whilst the rest of the structure remains elastic. When subjected to strong earthquakes, nevertheless, the building structure may exhibit plastic hinges before the dampers begin to work. In order to determine to which extent the use of viscously damped outriggers would avoid damage, both the host structure's hysteretic behaviour and the dampers' performance need to be evaluated in parallel. This article provides a parametric study on the factors that influence the distribution of seismic energy in tall buildings equipped with damped outriggers: First, the influence of outrigger's location, damping coefficients, and rigidity ratios core-to-outrigger and core-to-column in the seismic performance of a 60-story building with conventional and with damped outriggers is studied. In parallel, nonlinear behaviour of the outrigger with and without viscous dampers is examined under small, moderate, strong, and severe long-period earthquakes to assess the hysteretic energy distribution through the core and outriggers. The results show that, as the ground motion becomes stronger, viscous dampers effectively reduce the potential of damage in the structure if compared to conventional outriggers. However, the use of dampers cannot entirely prevent damage under critical excitations.

The impact of economic and social factors on the prevalence of hepatitis B in Turkey

Abstract: Viral Hepatitis is one of the major global health problems, affecting millions of people every year. Limited information is available on the impact of social and economic factors on the prevalence of Hepatitis B virus (HBV) in Turkey. This study, contrary to other studies in the literature, was undertaken with the aim of examining the Majority of the excluded data come from the volunteers. There are medical and the social-economic factors affecting the prevalence of HBV. This research, while taking medical factors as control variables, clarify the social and economic factors affecting the prevalence of HBV by utilising clinical data with the use of the Binary Probit Model (BPM). The BPM estimation is a powerful tool to determine not only the factors but explain also the exact impacts of each factor. The estimations of the BPM shows that economic and social variables such as age, gender, migration, education, awareness, social welfare, occupation are very important factors for determining HBV prevalence. Compared to the youngest population, the 46 to 66+ age group has a higher prevalence of HBV. The male respondents were 5% more likely to develop HBV compared to females. When region-specific differences are taken into account, migrating from the poorest parts of the country such as the eastern and south-eastern regions of Turkey are approximately 16% more likely to be infected. The welfare indicators such as a higher number of rooms in the respondent’s house or flat decreases the probability of having HBV and, relatively higher income groups are less likely to develop HBV compared to labourers. The Self-employed/Business owner/Public sector worker category are approximately 10% less likely to develop HBV. When people are aware of the methods of prevention of HBV, they are 6% less likely to be infected. Previous HBV infection history increases the probability of having HBV again B by 17%. These findings strongly suggest that the impact of social and economic factors on the prevalence of HBV is vital. Any improvements in these factors are likely to reduce prevalence of HBV.

Less pain, more gain: Volatility-adjusted residual momentum in international equity markets

Abstract: We offer a new type of momentum strategy — the volatility-adjusted residual momentum (VARMOM) — which is based on average past residuals scaled with their volatility. We demonstrate its application...

Effects of chitosan edible coatings enriched with sumac on the quality and the shelf life of rainbow trout (Oncorhynchus mykiss, Walbaum, 1792) fillets

Abstract: Effects of chitosan coating combined with sumac on the quality of rainbow trout (Oncorhynchus mykiss) fillets stored in refrigerated condition (4°C) for 12 days were evaluated. The treatments in this study were—T1, control; T2, chitosan: 2% w/v; T3, chitosan: 2% w/v and sumac: 1% w/v; and T4, chitosan: 2% w/v and sumac: 2% w/v. The shelf life of the samples were determined periodically using physicochemical (pH, peroxide value [PV], thiobarbituric acid [TBA], and total volatile basic nitrogen [TVB‐N]), microbiological (total viable counts [TVCs] and psychrotrophic bacteria), and sensory analyzes. During the storage period, T3 and T4 groups showed lower pH, PV, TBA, and TVB‐N values than T1 and T2 groups. The sensory results are in line with chemical and microbiological results. Treatment with 2% chitosan + 1% sumac and 2% chitosan + 2% sumac increased the shelf life of rainbow trout fillets by 6 days as compared to the control samples. PRACTICAL APPLICATIONS: To avoid the adverse effects of chemical preservatives and to answer natural and reliable product demands of the consumers, plant extracts and edible coatings are applied to increase the shelf life and to prevent the spoilage of fresh fish. The results of this study reported the efficacy of chitosan edible coating combined with sumac as a new natural preservative for improving the shelf life of rainbow trout fillets. The findings revealed that sumac extract combined with chitosan coating can be an alternative method to extend the shelf life, to preserve the quality and safety of fish, as a result of their good antioxidant and antimicrobial activity.

Strategies can be expensive too! The value spread and asset allocation in global equity markets

Abstract: Is the value spread useful for forecasting returns on quantitative equity strategies for country selection? To test this, we examine a sample of 120 country-level equity strategies replicat

Alternative Media and the Securitization of Climate Change in Turkey

Abstract: Studies on securitization dynamics in a growing number of sectors have been conducted, including securitization of climate change. However, a relatively understudied agent of securitization is medi...

Heat transfer and pressure drop characteristics of a plate heat exchanger using water based Al 2 O 3 nanofluid for 30° and 60° chevron angles

Abstract: Nanofluid is a new class of engineering fluid that has good heat transfer characteristics which is essential to increase the heat transfer performance in various engineering applications such as heat exchangers and cooling of electronics. In this study, experiments were conducted to compare the heat transfer performance and pressure drop characteristics in a plate heat exchanger (PHE) for 30° and 60° chevron angles using water based Al2O3 nanofluid at the concentrations from 0 to 0.5 vol.% for different Reynolds numbers. The thermo-physical properties has been determined and presented in this paper. At 0.5 vol% concentration, the maximum heat transfer coefficient, the overall heat transfer coefficient and the heat transfer rate for 60° chevron angle have attained a higher percentage of 15.14%, 7.8% and 15.4%, respectively in comparison with the base fluid. Consequently, when the volume concentration or Reynolds number increases, the heat transfer coefficient and the overall heat transfer coefficient as well as the heat transfer rate of the PHE (Plate Heat Exchangers) increases respectively. Similarly, the pressure drop increases with the volume concentration. 60° chevron angle showed better performance in comparison with 30° chevron angle.

A participatory product design process with children with autism spectrum disorder

Abstract: This study aims to explore the ways of involving children with autism in participatory product design processes. Due to the impaired skills of children with autism, a key aspect of the proc...

Green Permutation Flowshop Scheduling: A Trade- off- Between Energy Consumption and Total Flow Time

Abstract: Permutation flow shop scheduling problem (PFSP) is a well-known problem in the scheduling literature. Even though many multi-objective PFSPs are presented in the literature with the objectives related to production efficiency and customer satisfaction, studies considering energy consumption and environmental effects in scheduling is very seldom. In this paper, the trade-off between total energy consumption (TEC) and total flow time is investigated in a PFSP environment, where the machines are assumed to operate at varying speed levels. A multi-objective mixed integer linear programming model is proposed based on a speed-scaling strategy. Due to the NP-complete nature of the problem, an efficient multi-objective iterated greedy (IGALL) algorithm is also developed. The performance of IGALL is compared with model performance in terms of quality and cardinality of the solutions.

Contending narratives on the sustainability of nuclear energy in Turkey

Abstract: Sustainable development recently topped the universal agenda again when the United Nations adopted its Sustainable Development Goals on 25 September 2015. Yet, since the 1990s, the concept has prom...