5916 research outputs found
Sort by
Hotspots of floating plastic particles across the North Pacific Ocean
No full textThe pollution of the marine environment with plastic debris is expected to increase, where ocean currents and winds cause their accumulation in convergence zones like the North Pacific Subtropical Gyre (NPSG). Surface-floating plastic (>330 mu m) was collected in the North Pacific Ocean between Vancouver (Canada) and Singapore using a neuston catamaran and identified by Fourier-transform infrared spectroscopy (FT-IR). Baseline concentrations of 41,600-102,700 items km(-2) were found, dominated by polyethylene and polypropylene. Higher concentrations (factors 4-10) of plastic items occurred not only in the NPSG (452,800 items km(-2)) but also in a second area, the Papahanaumokuakea Marine National Monument (PMNM, 285,200 items km(-2)). This second maximum was neither reported previously nor predicted by the applied ocean current model. Visual observations of floating debris (>5 cm; 8-2565 items km(-2) and 34-4941 items km(-2) including smaller "white bits") yielded similar patterns of baseline pollution (34-3265 items km(-2)) and elevated concentrations of plastic debris in the NPSG (67-4941 items km(-2)) and the PMNM (295-3748 items km(-2)). These findings suggest that ocean currents are not the only factor provoking plastic debris accumulation in the ocean. Visual observations may be useful to increase our knowledge of large-scale (micro)plastic pollution in the global oceans.APDRC ; Helmholtz-funded infrastructure program FRAM ; Injury Prevention Research Center ; Bundesministerium für Bildung und Forschung ; Bundesministerium für Bildung und Forschung ; Helmholtz-Zentrum für UmweltforschungPublisher versio
Investigation of soot formation and agglomeration in ethylene/air jet diffusion flame with rank correlated SLW model
No full textEffect of radiation transfer is significant part of the overall heat transfer mechanism in sooting flames. The interaction between radiation transfer and soot formation considerably affects the combustion regime and the system efficiency. Spectral radiation models that account for the radiative effects of sooting flames need to be explored in detail to understand this phenomenon. This study numerically investigates the interaction between the radiation and soot formation in a sooting jet diffusion flame. In this regard, a rank correlated spectral linebased weighted sum of gray gases (RC-SLW) global model is implemented in Ansys Fluent and used for the radiation modeling of a jet diffusion flame and results were compared with the domain-based single gray gas weighted sum of gray gases (WSGG) model in Ansys Fluent RC-SLW model, including ethylene and acetylene flame radiation, showing considerable improvement in predicting the soot volume fraction compared to the domain-based single gray gas weighted sum of gray gases (WSGG) model available in Ansys Fluent. Increasing the number of gray gas bins in the RC-SLW model from 5 to 22 reduces the error in the maximum soot volume fraction from 30 % to 1 %. It was found that the effect of ethylene and acetylene radiation in the RC-SLW model has a minor effect on soot formation. Simulations without the effect of ethylene and acetylene radiation in the RC-SLW model underpredict the maximum soot volume fraction by 5 %. In addition, the effect of different possibilities of agglomeration of soot particles on the generated soot volume fraction was also investigated. Results showed that change of absorption coefficient due to change of soot agglomeration size affects maximum soot volume fraction by 6 %.TÜBİTA
The effect of immigration on housing prices: Evidence from 382 german districts
No full textThis study provides evidence of the causal impact of immigration on housing prices and rents using an extensive dataset from Germany that covers 382 administrative districts over the period 2004 - 2020. Employing a panel-data approach and a manually constructed Bartik instrument, we show that international migration has a significantly positive short-term effect on flat prices and rents. House prices are not significantly affected. We estimate that an increase in international migration of 1% of the initial district population causes a hike in flat prices of up to 3% as well as a hike in flat rents of about 1%. The increase in flat prices is more than twice as high as this at the lower end of the market, whereas the flat rental market demonstrates a more linear response. We also discover that immigration's impact on flat prices and rents does not significantly differ across rural and urban areas within the country.Alexander von Humboldt Foundation ; Institute for Employment Research ; Federation of Business Disciplines ; Toyo University in Tokyo ; Masaryk University in Brn
Uncitral model law on electronic transferable records: Is it an applicable legal framework for bills of lading under Turkish law?
No full textThe purpose of the “Model Law on Electronic Transferable Records” adopted by UNCITRAL on July 13, 2017, is to provide a legal framework for the digitisation of paper-based transferable documents or instruments. For this purpose, it is recognised that “functional equivalence” must be achieved between a paper-based document and an electronic record. The law also adopts the principle of “technological independence”. In accordance with this principle, the law does not recommend or endorse the use of a particular technology, method or product for electronic transactions. Similarly, the choice of paper-based documents covered by the law is left to national law. The important thing is that the document is transferable. However, UNCITRAL states that the use of electronic bills of lading in particular, should be facilitated because of its importance in maritime trade among transferable documents. It is also important for our country to adopt the MLETR to ensure international harmonisation and the development of international trade. For this reason, this study analyses whether the bill of lading qualifies as an electronic transferable record, as stipulated in the MLETR under Turkish law. In this context, it is explained whether the conditions of writing, signature, transferability, and control can be achieved in an electronic environment.Publisher versio
Coworker support in a sexual harassment climate: A conservation of resources perspective
No full textSexual harassment is still an issue in the hospitality industry, despite ample research on the topic. A sexual harassment climate - one that tolerates instances of unwanted sexual attention - produces negative impacts on employees' well-being, job satisfaction, emotional exhaustion, and engagement, which may lead to increased turnover, absenteeism, and decreased productivity. The purpose of this research is to investigate the role of a sexual harassment climate in employees' emotional exhaustion and employee engagement. Grounded in the conservation of resources theory, a moderated mediation analysis of a survey of 236 Turkish citizens who work in hotels confirmed that a sexual harassment climate led to more instances of unwanted sexual attention, which resulted in increased emotional exhaustion and decreased employee engagement due to the depletion of resources. Coworker support moderated this interaction, leading to a reduction in the negative impacts due to an increase in resources. Theoretical and practical implications are discussed.Publisher versio
A mutual catastrophe insurance framework for horizontal collaboration in prepositioning strategic reserves
No full textWe develop a mutual catastrophe insurance framework for the prepositioning of strategic reserves to foster horizontal collaboration in preparedness against lowprobability high -impact natural disasters. The framework consists of a risk -averse insurer pooling the risks of a portfolio of risk -averse policyholders. It encompasses the operational functions of planning the prepositioning network in preparedness for incoming insurance claims, in the form of units of strategic reserves, setting coverage deductibles and limits of policyholders, and providing insurance coverage to the claims in the emergency response phase. It also encompasses the financial functions of ensuring the insurer's solvency by efficiently managing its capital and allocating yearly premiums among policyholders. We model the framework as a very large-scale nonlinear multistage stochastic program, and solve it through a Benders decomposition algorithm. We study the case of Caribbean countries establishing a horizontal collaboration for hurricane preparedness. Our results show that the collaboration is more effective when established over a longer planning horizon, and is more beneficial when outsourcing becomes expensive. Moreover, the correlation of policyholders affected simultaneously under the extreme realizations and the position of their claims in their global claims distribution directly affects which policyholders get deductibles and limits. This underlines the importance of prenegotiating policyholders' indemnification policies at the onset of collaboration.Natural Sciences and Engineering Research Council of Canada (NSERC) ; Institute for Data Valorisation (IVADO) ; Institute for Data Valorisation (IVADO) ; TÜBİTA
A transdisciplinary approach and design thinking methodology: For applications to complex problems and energy transition
No full textIn this paper, we outline a transdisciplinary approach and design thinking methodology (TADTM) to tackle complex problems. Our premise is that these problems need a fundamental understanding of technological solutions and those for human interactions, business operations, financing, socioeconomic governance, legislation, and regulations. They must be approached by different decisionmakers from different disciplines to establish seamless interactions and structured teamwork. In this regard, we emphasize the need for a transdisciplinary framework that accounts for personal preferences based on human behavior as well as the traditional interdisciplinary frameworks. To test and prove our hypothesis, three case studies are discussed. Case Study 1 is based on our studies at a major medical establishment, and Case Study 2 is about the integrated engineering and architecture approach we used at our university campus. Case Study 3 is based on an ongoing project to lead industrial corporations to change their energy policies with practical energy efficiency measures and by adapting renewable/alternative energy adaptations for their operations. Developing creative solutions and strategies to decrease atmospheric greenhouse gas emissions requires such an energy transition framework and should involve every person, company, entity, and all governments. It can only be achieved with efforts on both local and global levels, which needs to convince (a) industries to change their traditional operation modalities, (b) people to alter their consumption behaviors, and (c) governments to change their rules, regulations, and incentives. The complexity and magnitude of this enormous task demand the coordination and collaboration of all stakeholders, as well as the need for technological innovations.Center for Energy, Environment, and Economy (CEEE) from Ozyegin UniversityPublisher versio
Learning from learning - design-based research practices in child-computer interaction
No full textInspired by the use of design-based research (DBR) in the learning sciences, in this paper, we discuss the promise of applying DBR in Child-Computer Interaction (CCI). As much research in CCI is related to learning interventions and educational contexts, we believe that DBR can be highly relevant for CCI, but that it has not yet reached its full potential in the field. We argue that DBR as a research approach can help mature the field, by explicitly grounding research design and interventions in theory, foster better impact beyond project completion, and bridge theory and practice through clarified knowledge contributions. Grounded in the characteristics of DBR, and based on a scoping review, this paper provides a timely snapshot of DBR literature, practices and research contributions in CCI research. Based on this, we will discuss further implications and opportunities of DBR in the CCI field.Independent Research Fund Denmark ; European Union's Horizon EuropePublisher versio
Pathways of democratic backsliding, resistance, and (partial) recoveries
No full textWe provide an analytical framework that identifies three distinct institutional pathways for democratic backsliding that culminate in executive aggrandizement: legislative capture, plebiscitary override, and executive power grabs. We also identify a fourth pathway of elite collusion that erodes democracy without necessarily concentrating powers in the executive. These four pathways reflect different combinations of ruling and opposition party strength, institutional legitimacy, and levels of popular support and political mobilization. The pathways also open and close different institutional and societal arenas where opposition forces can counter backsliding, and they create different opportunities, challenges, and dilemmas for democratic actors. The 15 case studies featured in this volume illustrate how backsliding occurs along these pathways, and how democratic actors achieved partial reversal in some cases. The cases also suggest focal points of resistance and institutional and programmatic reform that may be helpful to policymakers and advocates working to defend democracy
Sistem sistemlerinin otomatik testleri.
No full textThere are various kinds of software applications like mobile and Web applications. These applications have different types of user interfaces and user interaction methods. Hence, test automation tools are either dedicated or configured for a particular kind of application. Test scenarios can be implemented in the form of scripts and test execution can be automated separately for each application type. However, there are systems of systems that embody multiple types of applications deployed on various platforms. Test scenarios might cross-cut these applications to be controlled collectively in the test script. In this thesis, we propose an approach for testing cross-platform systems of systems. We present an application of it on a real system, involving a mobile and a Web application that are supposed to work in coordination. Our approach integrates a set of existing tools to facilitate test automation. It provides testers with a unified interface for developing test scripts that involve both mobile and Web applications. We conduct an industrial case study with participants from various backgrounds and show that our tool can reduce the testing effort significantly.Mobil ve Web gibi çeşitli platformlar için yazılım uygulamaları geliştirilmektedir. Bu uygulamaların farklı türde kullanıcı arayüzleri ve kullanıcı etkileşim yöntemleri bulunmaktadır. Bu nedenle, test otomasyon araçlarının belirli bir uygulama türüne özel geliştirilmesi veya yapılandırılması gerekmektedir. Test senaryoları komut betimleri şeklinde tanımlanabilmekte ve her uygulama türü için ayrı ayrı otomatik olarak çalıştırılabilmektedir. Ancak, farklı platformlarda konuşlandırılan birden fazla uygulama türünü bünyesinde barındıran sistemler sistemleri bulunmaktadır. Bir sistemler sistemi için oluşturulmuş test senaryolarında yer alan test adımlarının bu farklı platformlar ve uygulamamlar üzerinde toplu olarak kontrol edilerek çalışması gerekebilmektedir. Bu tez çalışmasında, birden fazla ve farklı tipte platform kullanan sistemler sistemlerini test etmek için bir yaklaşım önerilmektedir. Önerilen yaklaşımın gerçek bir sistem üzerinde uygulaması sunulmaktadır. Bu sistemde koordineli çalışması gereken bir mobil ve bir Web uygulaması bulunmaktadır. Yaklaşımımız, test otomasyonunu kolaylaştırmak için bir dizi mevcut aracı entegre etmektedir. Ortaya çıkan araç, test uzmanlarına hem mobil hem de Web uygulamaları üzerinde çalışabilen test komut betimlerini geliştirmek için bütünsel bir arayüz sağlamaktadır. Farklı altyapılardan gelen katılımcılarla gerçekleştirilien bir endüstriyel vaka çalışması ile, aracımızın test maliyetini önemli ölçüde azaltabildiği gösterilmektedir