5916 research outputs found
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Compact, dual circularly polarized satellite horn antenna and feed network covering full SATCOM ka-band
No full textIn this paper, compact, dual circularly polarized horn antenna and feed network covering the full SATCOM Ka frequency range including the military bands are presented. The design is intended to be used on the satellite side of a SATCOM link. As shown in Table I, simulated performance exhibits better than 30 dB cross-polarization discrimination (XPD), 30 dB return loss and 20 dB in-band isolation for both 17.7-21.2 GHz (transmit) and 27.5-31 GHz (receive) bands. The antenna section consists of a corrugated horn antenna and a radial mode converter, while the feed network section consists of six-port and five-port orthomode junctions, two different types of low-pass filters, H-plane bends, septum polarizers, taper, and adapters. © 2025 IEEE
Current perspectives of design thinking and design literacy rethinking design beyond disciplinary boundaries
No full textDesign thinking has become a cornerstone of 21st-century education and is emphasized across both design and non-design disciplines. Studies have long criticized design thinking as ambiguous because it has diverse definitions and employs a range of methodologies. Recently, the concept of design literacy has entered the literature. It is proposed that design literacy can foster the potential of design thinking to promote the development of the “new literacies” needed to drive change and transformation in an age facing global challenges such as climate change, technological transformations, and social inequality. This article highlights key themes from an international symposium exploring design’s foundational role in education, its connection to visual thinking and reasoning, the potential of interdisciplinary problem-solving, the human and social dimensions of design thinking, and the importance of design literacy for effective communication and collaboration among designers. This symposium is part of a broader research project based at Özyeğin University, Turkey, investigating how to cultivate design literacy knowledge and skills in early undergraduate curricula to foster an interdisciplinary and trans-professional learning environment before professional specialization.Høgskulen på Vestlandet ; TÜBİTAK ; International School of Design ; Shandong University ; ITU Department of Architecture ; Özyeğin Üniversitesi ; Technische Universiteit Delft ; Architecture InstitutePublisher versio
Joint optimization of connectivity, coverage, and revisit time in multi-UAV path planning
No full textMulti-UAV systems are deployed for many civil applications, such as search and rescue, surveillance, environmental monitoring, that require efficient area coverage and connectivity between UAVs and ground control station (GCS) to enable teamwork and information exchange. In dynamic missions, such as disaster management, or in case the sensors on the UAVs lead to uncertain measurements, it is desirable that whole or part of the area of interest is revisited by UAVs for information update or reliability. In this work, we propose a novel multiUAV path planning algorithm that incorporates revisit times into path decisions, without compromising coverage and connectivity requirements. We model the proposed planner by a multiobjective optimization problem and we provide an NSGA-II based solver that leads to a set of Pareto-optimal solutions. We compare our results with a benchmark path planner that only optimizes coverage and connectivity and show the tradeoffs between the proposed objective functions. We observe up to 4-fold improvement in terms of observed times between revisits.TÜBİTA
NTIRE 2025 challenge on night photography rendering
No full textThis paper presents a review of the NTIRE 2025 challenge on night photography rendering. The goal of the challenge was to find solutions that process raw smartphone images taken in nighttime conditions, producing output images that replicate the pipeline of a professional camera. Unlike the previous year's competition, this year a unique imaging setup was introduced: each scene was captured both by a smartphone and a professional camera with the help of a beam-splitter cube. There were two nominations: best objective quality and mean opinion score-based quality (see Fig. 1). terms of output quality were sorted by evaluation time (see Fig. 1). The solutions of the top 7 ranking participants outperformed the state-of-the-art solution in the low light enhancement field, RetinexFormer, according to objective rankings. More results can be found at https://nightimaging.org
Multi-stage scenario-based stochastic programming for managing lot sizing and workforce scheduling at Vestel
No full textThis study proposes a multi-stage stochastic production planning approach for a joint lot sizing and workforce scheduling problem under demand uncertainty. Scenario trees are used to model uncertainty in demand, and a multi-stage scenario-based stochastic linear program is developed. This model allows for both here-and-now and wait-and-see decisions providing flexibility for decision-makers to adjust production quantities according to the realized portion of demand and improve the overall effectiveness of production planning by better managing the number of active lines, workforce, and inventory levels. A matheuristic is developed for large-sized instances, which yields near-optimal solutions in practicable computation times. The proposed methods are demonstrated over a real data set taken from a Turkish home and professional appliances company, Vestel. The results show significant improvements in cost and CPU time performances for benchmark approaches, verifying the effectiveness of the proposed method.TÜBİTA
Measuring “sustainable development” in vernacular settlements: a case study Behramkale, Türkiye
No full textPurpose: The main objective of this paper is to critically assess sustainable development in the context of Behramkale, a vernacular village in Türkiye. Design/methodology/approach: Vernacular Heritage Sustainable Architecture analysis framework has been adopted to understand and assess vernacular architecture and sustainable development in Behramkale. Findings: The vernacular design of the old Behramkale settlement has shown more sustainable characteristics as compared to the new development area. Key findings show that trade-offs were made with respect to environmental and sociocultural aspects of sustainable development to achieve economic sustainability. Research limitations/implications: Future research with more in-depth interviews would be helpful to find out the inhabitants’ response to the conservation practices. Practical implications: Based on the research conducted, life cycle analysis and sustainable strategies of vernacular settlements can be useful tools to design, develop and improve old settlements, as well as newly established settlements. Social implications: Key lessons learned from conservation practices can help to identify well-adapted solutions to respond to the needs of local communities in Türkiye and similar vernacular settlements in the Mediterranean region. Originality/value: This paper critically assesses sustainable development in the context of vernacular architecture, heritage conservation and rural sustainability. Conservation practices in Türkiye are evaluated deeply as there is limited research in this field within the Mediterranean heritage conversation and sustainable development context
VO2‐Based dynamic coding metamaterials for terahertz wavefront engineering
No full textTÜBİTAK; University Research Foundation (BAP); Research and Application Center for Quantum Technologies (RACQUT) of IZTEC
Taking into account opponent's arguments in human-agent negotiations
No full textAutonomous negotiating agents, which can interact with other agents, aim to solve decision-making problems involving participants with conflicting interests. Designing agents capable of negotiating with human partners requires considering some factors, such as emotional states and arguments. For this purpose, we introduce an extended taxonomy of argument types capturing human speech acts during the negotiation. We propose an argument-based automated negotiating agent that can extract human arguments from a chat-based environment using a hierarchical classifier. Consequently, the proposed agent can understand the received arguments and adapt its strategy accordingly while negotiating with its human counterparts. We initially conducted human-agent negotiation experiments to construct a negotiation corpus to train our classifier. According to the experimental results, it is seen that the proposed hierarchical classifier successfully extracted the arguments from the given text. Moreover, we conducted a second experiment where we tested the performance of the designed negotiation strategy considering the human opponent's arguments and emotions. Our results showed that the proposed agent beats the human negotiator and gains higher utility than the baseline agent.Chist-Era ; TÜBİTA
Location-based examination of the characteristics of university campuses in İstanbul
No full textPurposeThe study investigates the connections that university buildings and campuses establish with their environments and the effects of their environments on universities. Many factors influence the location of universities in a particular region. The initial university settlement and the subsequent facilities needed by university branches, colleges, or faculties are related to each other by the time parameter Istanbul, a historical city that is also Turkey's largest, hosts several state and founding universities. This study investigates the connections between the urban areas where university campuses in Istanbul are located within the city and the specific characteristics of universities.Design/methodology/approachWe evaluate the data on university locations in the city to determine the relationships between their establishment date, size, type, place of location in the city, and unique characteristics. The analysis is based on data for occupancy rate, satisfaction level, university ranking, and space area per student.FindingsResults: Campus areas are affected by the availability of public transport and other amenities in urban areas. There are also interactions between meeting students' satisfaction, university ranking, and public perceptions of the university and campus location in the city.Originality/valueThis study investigates the connections between the urban areas where university campuses in Istanbul are located within the city and the specific characteristics of universities
Integrating logistics planning and population sampling decisions for humanitarian needs assessment
No full textAfter a disaster, humanitarian organizations must quickly assess the needs of affected populations spread across a large area to inform effective relief distribution. This process involves site visits and collecting information through interviews, where balancing travel time and assessment accuracy is critical. This paper introduces the Assessment Routing Problem with Coverage and Accuracy, which addresses the logistical planning and sampling decisions of a post-disaster needs assessment team. The problem involves determining which sites to visit, in what sequence, and how much time to spend at each site to collect information within a total assessment time limit. We present a mathematical model that balances site coverage and sampling accuracy, and propose a constructive heuristic and a tabu search algorithm to efficiently solve large-scale instances. Computational experiments demonstrate that the tabu search algorithm can quickly obtain optimal or near-optimal solutions for large instances, while the performance of the heuristic is influenced by network topology. We illustrate the effectiveness of our approach through a case study based on the 2011 Van Earthquake in Turkey. Our findings emphasize the trade-offs involved in prioritizing certain areas and the advantages of leveraging reliable prior information in the assessment process to achieve better site coverage and sampling accuracy.Publisher versio