5916 research outputs found
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Mass flow rate control of solenoid-based injectors
No full textThis paper presents a mass flow rate control method for solenoid-based injectors in open-loop, i.e. without physical
sensor feedback. Measuring the mass flow rate in injectors is important because the performance of the injector
determines fuel consumption and emissions. While it is possible to perform this control using different types of sensors,
this would increase the cost and reduce the reliability. With this study, it was aimed to control the mass flow rate
of solenoid-based injectors using continuous switching control to regulate the injector’s needle displacement without
using sensors. For this purpose, a solenoid-actuated injector prototype was created. Model-based estimators were
used to determine the states of the injector, while a super-twisting sliding mode controller was used to track the desired
mass flow rate references. The results of the experiments showed that tracking for sinusoidal, triangular, and square
trajectories yielded a mass flow rate percent error of less than 1.06. The proposed open-loop control algorithm can be
used to track different mass flow rate references in internal combustion engines.Post prin
Swelling phenomenon in rubber weatherstrip manufacturing under real process conditions imposed in a commercial extrusion line
No full textWe investigated the swelling under different process and boundary conditions in a commercial weatherstrip extrusion line. For the experimental investigations, we used two extrusion-dies and three compounds. An in-situ laser optical measurement set-up was used immediately after the die-exit to measure die-swelling. The traditional projection-based measurement method was used at the end of the line to measure the swelling of the cured extrudate. A dimensionless number, namely Extrudate Speed Number (ESN) was defined as the ratio of the average speed of extrudate at the die exit to the puller speed. We used ESN to analyze die-swelling. Two extrusion-dies were designed to extrude strips with axisymmetric and rectangular cross-sections with low and high aspect ratios. We tested solid and sponge compounds for their swelling behavior. Independent of the die shape and compound, it is found that dimensionless swelling tends to increase with the increase of ESN and vice versa. However, the gradient of the dimensionless swelling with respect to ESN can differ depending on the compound, extrudate shape, and the direction for which swelling is measured
Product market competition and the value of diversification
No full textI examine how industry concentration affects the value of diversification. I find that con- glomerates that operate mainly in concentrated industries (concentrated conglomerates) have higher diversification values. Using tariff reductions as competitive shocks, I show that concentrated conglomerates experience significant decline in their valuations and respond aggressively to threats in less-competitive industries.Publisher versio
Bidding support by the pocket negotiator improves negotiation outcomes
No full textThis paper presents the negotiation support mechanisms provided by the Pocket Negotiator (PN) and an elaborate empirical evaluation of the economic decision support (EDS) mechanisms during the bidding phase of negotiations as provided by the PN. Some of these support mechanisms are offered actively, some passively. With passive support we mean that the user only gets that support by clicking a button, whereas active support is provided without prompting. Our results show, that PN improves negotiation outcomes, counters cognitive depletion, and encourages exploration of potential outcomes. We found that the active mechanisms were used more effectively than the passive ones and, overall, the various mechanisms were not used optimally, which opens up new avenues for research. As expected, the participants with higher negotiation skills outperformed the other groups, but still they benefited from PN support. Our experimental results show that people with enough technical skills and with some basic negotiation knowledge will benefit most from PN support. Our results also show that the cognitive depletion effect is reduced by Pocket Negotiator support. The questionnaire taken after the experiment shows that overall the participants found Pocket Negotiator easy to interact with, that it made them negotiate more quickly and that it improves their outcome. Based on our findings, we recommend to 1) provide active support mechanisms (push) to nudge users to be more effective, and 2) provide support mechanisms that shield the user from mathematical complexities.H2020 ICT48 ; Italian Ministry for Universities and Research ; Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung ; Fonds National de la Recherche Luxembourg ; CHIST-ERA ; Ministerie van Onderwijs, Cultuur en Wetenschap ; Nederlandse Organisatie voor Wetenschappelijk Onderzoek ; TÜBİTA
Deterministic neural illumination mapping for efficient auto-white balance correction
No full textAuto-white balance (AWB) correction is a critical operation in image signal processors for accurate and consistent color correction across various illumination scenarios. This paper presents a novel and efficient AWB correction method that achieves at least 35 times faster processing with equivalent or superior performance on high-resolution images for the current state-of-the-art methods. Inspired by deterministic color style transfer, our approach introduces deterministic illumination color mapping, leveraging learnable projection matrices for both canonical illumination form and AWB-corrected output. It involves feeding high-resolution images and corresponding latent representations into a mapping module to derive a canonical form, followed by another mapping module that maps the pixel values to those for the corrected version. This strategy is designed as resolution-agnostic and also enables seamless integration of any pre-trained AWB network as the backbone. Experimental results confirm the effectiveness of our approach, revealing significant performance improvements and reduced time complexity compared to state-of-the-art methods. Our method provides an efficient deep learning-based AWB correction solution, promising real-time, high-quality color correction for digital imaging applications
Spatial reason of the state: the role of space in protest repression in Turkey
No full textBetween 2007 and 2019 the Turkish regime used protest bans extensively in order to impede collective mobilization. In this paper, drawing on Michel Foucault’s discussion of raisond’état and an original dataset of protest bans, we examine these legal practices as part of the state’s repertoire of protest repression. We point to two limits against the indefinite extension of state regulation that Foucault identifies: an external limit posed by public law and regime of rights, and an internal limit that questions the effectiveness of ‘too much’ government. We argue that authorities use spatial control as a technology to negotiate these two limits. Specifically, authorities deploy the state’s prerogative of regulating public space as a ‘politically neutral’ legal technology to reconcile the banning of protests with the external limit posed by freedom of assembly. Spatial control also works as an effective form of government to negotiate the internal limits of raisond’état. We use illustrative examples to unpack the mechanisms of how spatial technologies neutralize protests to bolster an authoritarian regime. The study contributes to empirical research on protest repression as well as theoretical discussions on the rationalities of government by expanding the geographical scope of existing research to an autocratizing context.Boğaziçi Üniversitesi Research Fund ; Seren Selvin Korkmaz and Özlem Tunçel ; Stiftung Wissenschaft und Politik ; Özyeğin Universit
Out-of-band analysis of GFDM systems based on different self-interference types
No full textThis paper studies the impact of out-of-band (OOB) emission and interferences on the generalized frequency division multiplexing (GFDM) systems. Specifically, we analyze the effects of two types of independent self-interference, namely inband and adjacent subcarrier interference, on the OOB performance. We analytically derive mathematical expressions for OOB emission and sufficient conditions for reducing OOB. We investigate the effects of different prototype filters on the OOB performance based on the new formulation of the GFDM system. Our numerical experiments show that the OOB performance is independent of the modulation order and depends on the type of prototype filter and its orthogonality
Imagining decent work towards a green future in a former forest village of the city of İstanbul
No full textThis paper addresses issues pertaining to the future of work and sustainability through the lens of a case study of ecological deterioration and how it destroys and creates green jobs in a forest village of Istanbul. As elsewhere in major urban centres of developing countries, the hyper-expansion of city regions due to authoritarian developmentalism fosters the state-led construction sector in Turkey. Growth-driven economic policies continue to have adverse effects on the environment, resulting in deforestation among an array of ecological damage. Based on a qualitative analysis of oral history interviews and observations informed by a larger interdisciplinary research project, we observe resilience in the forest village under scrutiny as certain types of work are abandoned, and new forms are created by adaptation to the ecological and social conditions. The perceptions of changing conditions by locals vary across existing ethnic, gender, and class hierarchies in the local community. Moreover, our findings indicate that the types of work available in the village prior to urban transformation were not all decent or green. In face of ongoing ecological deterioration in a (formerly) forest community, participatory micro-initiatives, and grassroots, utilizing local community projects emerge that nevertheless pursue a green and just transition. We focus on one such initiative, the Community Fungi platform, to demonstrate the possibility of working towards a collective imagination of a green future inspired by past but unforgotten sustainable communal practices, in the context of the forest village under scrutiny in this paper.Publisher versio
Managing disease containment measures during a pandemic
No full textThroughout the current COVID-19 pandemic, governments have implemented a variety of containment measures, ranging from hoping for herd immunity (which is essentially no containment) to mandating complete lockdown. On the one hand, containment measures reduce lives lost by limiting the disease spread and controlling the load on the healthcare system. On the other hand, such measures slow down economic activity, leading to lost jobs, economic stall, and societal disturbances, such as protests, civil disobedience, and increases in domestic violence. Hence, determining the right set of containment measures is a key social, economic, and political decision for policymakers. In this paper, we provide a model for dynamically managing the level of disease containment measures over the course of a pandemic. We determine the timing and level of containment measures to minimize the impact of a pandemic on economic activity and lives lost, subject to healthcare capacity and stochastic disease evolution dynamics. On the basis of practical evidence, we examine two common classes of containment policies—dynamic and static—and we find that dynamic policies are particularly valuable when the rate of disease spread is low, recovery takes longer, and the healthcare capacity is limited. Our work reveals a fundamental relationship between the structure of Pareto-efficient containment measures (in terms of lives lost and economic activity) and key disease and economic parameters such as disease infection rate, recovery rate, and healthcare capacity. We also analyze the impact of virus mutation and vaccination on containment decisions
A new path following scheme: safe distance from obstacles, smooth path, multi-robots
No full textRobot routing is one of the most important topics in mobile robotics. The goal is to find a continuous path from an initial position to an end destination that is collision-free and optimal or near-optimal. Due to the growing trend of using automatic moving tools in industrial automation, and their application for various purposes such as transportation of goods, and service in industrial and hospital environments, many researchers have decided to conduct research in this field and route planning. The main challenge is to find a short route with a lack of collision with obstacles. This study examines path design for mobile robots and proposes a new and efficient idea for routing. Besides the short distance of the route and lack of collision with obstacles, the proposed method investigates other factors such as the safe distance from obstacles, path smoothness, and multiple robots. The results show the superior precision and speed of the proposed algorithm compared to similar algorithms. The suggested approach finds the shortest path with a safe distance from obstacles, in a minimum time. The major contributions of this method are summarized below: (1) a biogeographical algorithm is formulated for robot routing. (2) To improve the basic biogeographical algorithm, basic operations of the particle swarm optimization and genetic algorithm are integrated with it. (3) In addition to the shortest path problem, other problems such as path smoothness with a new idea and the safe distance from obstacles are included. Path smoothing is performed without involving it in the cost function, and merely through interpolation of the points found by the algorithm. (4) The proposed algorithm results in a good efficiency and finds the appropriate solution in a few iterations