5916 research outputs found
Sort by
Branching brownian motion in an expanding ball and application to the mild obstacle problem
No full textWe first study a d-dimensional branching Brownian motion (BBM) among mild Poisso-nian obstacles, where a random trap field in Rd is created via a Poisson point process. The trap field consists of balls of fixed radius centered at the atoms of the Poisson point process. The mild obstacle rule is that when particles are inside traps, they branch at a lower rate, which is allowed to be zero, whereas when outside traps they branch at the normal rate. We prove upper bounds on the large-deviation probabilities for the total mass of BBM among mild obstacles, which we then use along with the Borel-Cantelli lemma to prove the corresponding strong law of large numbers. Our results are quenched, that is, they hold in almost every environment with respect to the Poisson point process. Our strong law improves on the existing corresponding weak law in [Ann. Inst. Henri Poincaré Probab. Stat. 44 (2008), 490–518]. We also study a d-dimensional BBM inside subdiffusively expanding balls, where the boundary of the ball is deactivating in the sense that once a particle of the BBM hits the moving boundary, it is instantly deactivated but will be reactivated at a later time provided its ancestral line is fully inside the expanding ball at that later time. We obtain a large-deviation result as time tends to infinity on the probability that the mass inside the ball is aytpically small. An essential ingredient in the proofs of the strong law of large numbers for BBM among mild obstacles turns out to be the large-deviation result on the mass of BBM inside expanding balls.Publisher versio
Emotion regulation in emotionally focused therapists working with high-conflict couples
No full textGuided by the Person-of-the Therapist Training (POTT) Model, the current qualitative study explores emotional experiences and emotion regulation strategies of emotionally focused trained therapists who work with high-conflict couples in Turkey. Twenty-one therapists who completed at least the externship in emotionally focused couple therapy (EFCT) and had prior or current clinical experience working with high-conflict couple(s) were recruited through various social media platforms and professional organizations' listservs. Semistructured individual interviews were conducted, audio-recorded, and transcribed verbatim. Thematic analysis of the qualitative data revealed five main themes: (1) Different Compelling Emotional Experiences of the Therapists, (2) Sun After Storm, (3) Triggers of Therapists' Emotions, (4) Perceived Adaptive Emotion Regulation Strategies, and (5) Positive Impact of the Therapist's Regulation Strategies on the Therapy Process. Overall, the findings supported the three phases of the POTT model: namely, knowledge of self, access to self, and use of self. Our study demonstrates the need for integrating self-of-the-therapist work into the clinical practice, training, and supervision of therapists working with distressed couples.Publisher versio
Economic implications of overvoltage mitigation methods in PV-rich LV networks by distribution locational marginal pricing
No full textThis paper focuses on Distribution Locational Marginal Pricing (DLMP) as a financial tool within LV networks, exploring its susceptibility to voltage deviations and losses, particularly within PV-rich environments. Three overvoltage mitigation methods are investigated for their impact on DLMP and the total cost-to-load. The study assesses the effects on buses proximal and distal to the transformer and clarifies the total losses incurred by each method. A comparative analysis of the daily cost-to-load is conducted, providing insights into the economic implications of overvoltage mitigation strategies. By interpreting the relations among overvoltage mitigation methods, DLMP, and cost-to-load, this paper contributes to an improved understanding of the financial dynamics within PV-rich distribution networks
Evaluation of indoor daylighting performance changes in a historical khan building in istanbul
No full textThe daylighting feature of historical buildings can be accepted as an intangible heritage since it contributes to the unique atmosphere of the buildings. However, with the change of the built environment and the change of the historical building itself, the level of daylight intake of historical buildings changes. This study contributes to the field by revealing the daylighting performance changes of a historical khan building which has a unique architectural characteristics. The changes in the daylighting levels of Buyuk Yeni Khan, one of the largest historical khans in Istanbul, are examined through its modifications. Using 3D Lidar scanning technology, the current state of the khan is scanned. The daylight intake and glare analyzes of the khan for its current and original states are made through simulations, and the values found are compared. DA, cDA, UDI, sDA and DGP metrics are used in the simulations. As a result, due to the changes such as enlargements along the arcades, additional overhangs and the change of window ratios of the facades of the rooms on the ground floor, the rooms of the khan have different daylighting values compared to its original state.Publisher versio
A runtime manager integrated emulation environment for heterogeneous soc design with RISC -V cores
No full textRISC-NI based architectures have gained attention for deployment on platforms from SoC to HPC scale to meet the demands of a wide range of computational workloads that may require specialized hardware tailored to their specific performance goals. In previous works, we introduced CEDR, an opensource, unified compilation and runtime framework designed to facilitate productive hardware-agnostic application deployment on heterogeneous architectures, and lift the barriers to research on the design and evaluation of scheduling heuristics and accelerators for heterogeneous systems. In this study, we demonstrate the capability of CEDR in supporting heterogeneous systems composed of RISC-V cores and a pool of accelerators. We investigate the impact of employing customized lightweight RISC-V cores for managing accelerators individually. Such management approach, compared to centralized accelerator management model, scales down the stress on the runtime environment where compute resources are shared among multiple applications each with varying degrees of task-level parallelism. We perform evaluations on a heterogeneous SoC emulated on the Xilinx Virtex-7 FPGA based on execution of applications from radar, signal processing, and autonomous vehicles domains. We observe that releasing CPU-based compute cores from accelerator management through lightweight RISC-V cores results with up to 47% reduction in time spent on accelerator management. Since CPU-based compute cores exclusively become available for application task execution and contention on resource management is reduced, we observe speedup of up to 2.2x in application execution time based on experiments conducted with workloads consisting of dynamically arriving real-life application scenarios.United States Department of Defense US Air Force Research Laboratory ; United States Department of Defense Defense Advanced Research Projects Agency (DARPA
Impact of prioritized HTTP/3 transport on low-latency live streaming
No full textTimely delivery is central to low-latency live streaming. In November 2023, the Internet-Draft for HTTP Live Streaming (HLS) added support for HTTP/3 (H3) and required the use of RFC 9218 (extensible priority scheme) with H3 servers delivering low-latency HLS (LL-HLS) content. The Internet-Draft further mandated several prioritization rules on the playlists, media segments and variant streams. This work is the first experimental study in this domain, with a focus on demonstrating the effectiveness of these rules and evaluating whether RFC 9218 emerges as a viable solution for optimizing lowlatency live streaming experiences
V2RA: A grid -based rate - adaptation logic for volumetric video
No full textThe quality-bitrate relationship is not necessarily as straightforward in volumetric video content as in 21) video. This is caused by the different volumetric video components affecting the overall quality of the content disproportional to their bitrates.Tiwrefore, switching to a combination of higher bitrate components to improve the quality may not always produce the best outcome when making rate adaptation decisions far streaming. to address tins problem, this study proposes a new rate -adaptation logic named Voluinetric Video Rate Adaptation (V2RA). The experiments performed using the MPEG Inunersive Video (MIV) standard show that V2RA can significantly reduce bandwidth consumption at the expense of an acceptable loss in quality. In some cases, V2RA even achieves quality gains together with bandwidth savings.Publisher versio
Climate-resilient building energy efficiency retrofit: evaluating climate change impacts on residential buildings
No full textBuildings have the potential to mitigate climate change effects by integrating energy-efficient solutions. Building resilient design strategies based on forthcoming weather predictions offers an effective means of adaptation. The study focuses on the impact of climate change on residential buildings in Istanbul and Izmir, two Turkish cities with distinctive climate characteristics. By creating future weather scenarios and conducting dynamic simulations, buildings ' and improvement measures ' performance under RCP 4.5 and RCP 8.5 climate scenarios and short- and long-term periods are evaluated. The findings reveal varying degrees of climate change impact on the two regions, with decreased heating degree days (HDDs) and increased cooling degree days (CDDs). Notably, the RCP 8.5 scenario projects significant temperature increases, with a rise of 4.3 degrees C in Istanbul and 5 degrees C in Izmir, leading to profound consequences for buildings. The CDD can be doubled in July and reach 292 in Izmir and quadrupled, reaching 158 in Istanbul. Without retrofit, in a well-naturally ventilated building, primary heating energy consumption can be decreased by 36 -41 %, while primary cooling energy consumption tripled in both cities. With the aid of improvements, a - 5 -6 degrees C decrease was observed in the highest temperature predictions in naturally ventilated spaces in summer in Istanbul, while a - 4 -5 degrees C decrease was observed in Izmir.Publisher versio
Akademik yayınların yaşam döngüsünde kurumsal akademik arşivleri yeniden düşünmek
No full textPosterde, bilimsel ve akademik iletişimde bazen başlangıç bazen varış noktası olan akademik arşivlerin bu yayın yaşam döngüsündeki yerine dikkat çekilmek istenmektedir. Akademik yayın süreçlerinin tüm dünyada büyük gelişme kaydeden açık bilim ve açık erişim kapsamında değerlendirilmesi ve değişen kütüphanecilik hizmetleri ile yeni kütüphaneci rollerine vurgu yapılması amaçlanmıştır. Bununla beraber bu döngüde tüm paydaşların birlikte çalışabilirlik olgusuna sağladığı katkı ele alınacaktır
Numerical analysis of the heating zone of a container glass annealing furnace: Effect of circulation fan speed on the heating effectiveness of the furnace
No full textAnnealing is a heat treatment process commonly carried out in a continuous annealing furnace. While radiative heat transfer is the primary mode of heat transfer in annealing, convective heat transfer also makes a noteworthy contribution. In this numerical study, the effect of the circulation fan flow rate on the heating characteristics of the heating zone of a continuous glass bottle annealing furnace was studied. Heat transfer process is solved by modeling the convection inside the furnace and conduction in the solid glass in separate solvers and by coupling these solvers including radiation in an iterative scheme. The radiation heat transfer between the furnace walls and glass bottles is solved using an in-house developed graphic accelerated Monte Carlo ray tracing algorithm-based model. The glass bottle rows are included as porous zones in the furnace. The flow blockage due to the bottles and convective heat transfer between the bottles and furnace air are calculated using the average flowconditions inside each porous zone. Results clearly show the effect of the circulation fan volumetric flow rate on the shares of the radiative and convective heating mechanisms in the process. Increasing the volumetric flow rate enhances the convective heat transfer rate on the glass which results in lower furnace wall temperatures and it also leads to a considerably more uniform temperature distribution within the glass bottles at the zone outlet. The increased uniformity in the glass temperatures implies a reduction in the soaking zone lengthwhichwould reduce the investment and operational cost of the furnace