4653 research outputs found
Sort by
Maximum-Likelihood Detection With QAOA for Massive MIMO and Sherrington-Kirkpatrick Model With Local Field at Infinite Size
No full textQuantum-approximate optimization algorithm (QAOA) is promising in Noisy Intermediate-Scale Quantum (NISQ) computers with applications for NP-hard combinatorial optimization problems. It is recently utilized for NP-hard maximum-likelihood (ML) detection problem with challenges of optimization, simulation and performance analysis for nxn multiple-input multiple output (MIMO) systems with large n . QAOA is recently applied by Farhi et al. on infinite size limit of Sherrington-Kirkpatrick (SK) model with a cost model including only quadratic terms. In this article, we extend the model by including also linear terms and then realize SK modeling of massive MIMO ML detection. The proposed design targets near ML performance while with complexity including O(16(p)) initial operations independent from problem instance and size n for optimizing QAOA angles and O(n(2)p) quantum operations for each instance. We provide both optimized and extrapolated angles for p is an element of[1,14] and signal-to-noise (SNR) = 4 for 25x25 and 12x12 MIMO systems modulated with BPSK and QPSK, respectively. We present two conjectures about concentration properties of QAOA and near-optimum performance for next generation massive MIMO systems covering n<300 .Engineering, Electrical & Electronic || Telecommunication
Extended exergy analysis of a novel integrated absorptional cooling system design without utilization of generator for economical and robust provision of higher cooling demands
No full textThe focus of this study is on designing a novel system for the provision of high-capacity cooling and heating loads (4000 kW) with the utilization of absorption technology to increase economic viability and COP value of existing cooling plants via lower-grade waste heat sources (70 degrees C-90 degrees C). To achieve this aim, in the novel system, an integration including the LiBr-water solution based absorptional heat transformer (AHT), and absorptional cooling cycle (ACC), and flat plate solar collector (FPSC) systems was proposed. In the integration, the utilization of the generator in the cooling cycle was avoided with the interaction of the high-temperature LiBr-water solution (120 degrees C-150 degrees C) from the AHT system and ACC system evaporator. In this way, both the additional cost of the boiler and heat source and the enhancement of economic viability and COP value were achieved. Energy, economic, traditional, and extended exergy, sustainability, and environmental analyses were implemented in this novel system. The COP value for the cooling system was determined to be 3.10 from energy analysis. This result forms a significant indicator for achieving of the main focus of the current study with the proposed novel system. The annual heating and cooling duty generations with this novel system were computed as 52.37 GWh and 52.40 GWh, respectively. In the context of economically comparing the proposed system to other plants with similar scale that already exist, the initial overall expenditure, yearly operational expenses, and the time it takes to recover the investment for the proposed system were set at 3.12 million, and 1.75 years, respectively. It is worth noting, though, that these figures fall within the range of 5 - 7 million, and 5 - 10 years, respectively, for the currently operational plants. This result indicated that the proposed system provides a robust alternative to the existing cooling-heating cogeneration systems in terms of main output generation and is more economically viable. Also, the novel system gained annually US$3.89 million in energy costs. The conventional exergy analysis results were summarized by forming an exergy flow and loss diagram, namely, the Grassmann diagram. In addition, in this current study, the novel extended exergy flow diagram indicating extended exergy content components, energy carriers of the proposed system, and exergy product rate streams was also proposed and drawn for the proposed system.Thermodynamics || Energy & Fuels || Mechanic
VICTIMS OF COMMEMORATION: THE ARCHITECTURE AND VIOLENCE OF CONFRONTING THE PAST IN TURKEY
No full textArchitectur
Complete group law for genus 2 Jacobians on Jacobian coordinates
No full textThis manuscript provides complete, inversion-free, and explicit group law formulas in Jacobian coordinates for the genus 2 hyperelliptic curves of the form y 2 = x 5 + a 3 x 3 + a 2 x 2 + a 1 x + a 0 documentclass[12pt]{minimal} usepackage{amsmath} usepackage{wasysym} usepackage{amsfonts} usepackage{amssymb} usepackage{amsbsy} usepackage{mathrsfs} usepackage{upgreek} setlength{oddsidemargin}{-69pt} begin{document}end{document} over a field K with char ( K ) not equal 2 documentclass[12pt]{minimal} usepackage{amsmath} usepackage{wasysym} usepackage{amsfonts} usepackage{amssymb} usepackage{amsbsy} usepackage{mathrsfs} usepackage{upgreek} setlength{oddsidemargin}{-69pt} begin{document}end{document} . The formulas do not require the use of polynomial arithmetic operations such as resultant, mod, or gcd computations but only operations in K.Computer Science, Theory & Method
Looking into Mid-Century Modern Furniture Design in Turkey through Oral History
No full textFurniture design has traditionally taken second place to architecture in historiography, especially in Turkey. The consequent limited furniture-related academic publications, original material, and documentation make it necessary to probe further into Turkey's modern furniture history. The DATUMM (Documenting and Archiving Turkish Modern Furniture) Project (datumm.org) (2013-) was initiated to help fill this gap in the history of modern furniture design in Turkey between 1930 and 1975. Other than highlighting furniture, the documentary aimed to initiate an oral history project that has not been conducted in the design realm before in Turkey. Oral history interviews were conducted with thirteen contributors, including designers, artisans, and producers, who have significantly influenced Turkish modern furniture design. This method gave a voice to those who have not been able to contribute to Turkey's design history and reveals individual stories to construct a more comprehensive narrative. These interviews thus provide valuable opportunities to grasp what is hidden in the written history, and understand the shared stories, experiences, and struggles of designers to create a flourishing discipline from almost nothing.Ar
Analysing of the territorial competitiveness index in Izmir through dynamic model
No full textTransition towards more sustainable and resilient economies is crucial to provide sustainable economic development by considering environmental protection and social well-being. There is an increasing focus on the concept of territorial competitiveness that encompasses the aspects of environmental, social, and economic sustainability. Thus, this study aims to analyse the factors affecting the territorial competitiveness index in the Izmir town. To facilitate a comprehensive analysis of the factors that impact territorial competitiveness, a systematic approach is employed through the use of a system dynamic model. This model enables the exploration of the complex and dynamic relationships between key parameters, providing insights into their interdependencies and how they cooperatively influence the territorial competitiveness index. The results show that Gross Domestic Product growth rate, renewable energy production and technology innovation index is increased rapidly. This increase caused by development of social well-being in the region. However, sustainable land use and waste is decreased and therefore CO2 is increased in the 2010 and 2027. Besides, territorial competitiveness index is expected to increase till 2027 since subsidies in energy and material (re)use, efficient use of resources (circular economy), achievement of economic development and technological investments. Governments and businesses should adopt sustainable strategies for improving territorial competitiveness index and balancing economic growth with environmental protection and social welfare in the regional context.Environmental Studie
One perspective or two? Viewpoint dependency in visual events
No full textViewpoint dependency in dynamic events is still an open question. Movies present a unique case of complex visual stimuli where consecutive shots are filmed from multiple viewpoints. In the present study, we have examined whether people remember viewpoint-specific information in movie-like visual scenes. We have used naturalistic activities which involved two actors where a) the sequence is presented from one or both actors' viewpoints and b) the individual actions were in a natural order or they were scrambled. The results indicated that memory for individual shots decreased when the sequence was presented from both actors' perspectives. Also, people were mostly unaware of the order manipulation, and reordering the individual actions did not lead to a decrease in memory performance. The results favor the film-form model, which suggests that the spatial relations in movie scenes are represented by taking the first shot of a scene as the basis and incorporating the views in subsequent shots accordingly. This argues for an economical encoding in visual events, which favors narrative continuity over spatial relations.Psychology, Multidisciplinar
Political economy of Turkey's pivot to Asia
No full textThis article examines T & uuml;rkiye's increasingly complex relations with Asia from a political economy perspective, capitalizing on the notions of semi-periphery and sub-imperialism in an era marked by the crisis of globalization and a relative decline of US economic and technological power. It contends that the complexity of T & uuml;rkiye-Asia relations and associated changes in Turkish foreign policy should be examined within the shifting global and domestic political-economic conditions and the changing relations between countries.Area Studie
A parametric study on energy, exergy and exergoeconomic assessments of a modified auto-cascade refrigeration cycle supported by a dual evaporator refrigerator
No full textThis paper presents an evaluation of the energetic, exergetic, and exergoeconomic performances of a modified auto -cascade refrigeration (MACR) cycle integrated with a dual evaporator refrigerator (DER) to determine optimum operating conditions. DER facilitates a reduction in the compression ratio, allowing the low -boilingpoint component to release more heat before entering the evaporator. In this study, the R170/R290 refrigerant mixture, which has a low global warming potential but an explosion risk, was used. The main purpose of this study is to eliminate the risk of explosion by reducing the compressor discharge temperature and at the same time to enhance the overall cycle performance. To achieve this, DER is used instead of air-cooled coils, which have limited cooling performance. Despite an ambient temperature of 35 degrees C, the MACR cycle achieved a remarkable 51.29 % reduction in compressor discharge temperature when the separator inlet temperature was reduced to 10 degrees C by the DER. It also results in a 72.73% reduction in compression work rate and a significant 137.02% increase in cooling effect compared to the conventional auto -cascade refrigeration cycle. Furthermore, the MACR cycle exhibits notable improvements in total exergy destruction rate and exergy destruction cost rate with a 75.23% and a 76.07% reduction, respectively. Simultaneously, the exergy efficiency and the exergoeconomic factor increased by 266.67% and 179.15%, respectively. The MACR cycle achieves optimum energy and exergy performance with a 60% R170 mass fraction and 0.50 vapor quality, resulting in 1.429 kW compression work rate, a COP of 0.70, and an exergy efficiency of 26.66 %. The optimum exergoeconomic performance is achieved with a 40% R170 mass fraction and 0.50 vapor quality.Thermodynamics || Energy & Fuel
Linkage Theory and Autocratic Regime-Survival Strategies in a Post-Liberal Order: The Case of Authoritarian Middle Power Turkey (2013-2022)
No full textAt a time of authoritarian drift in many parts of the world characterizing a post-liberal order, this paper aims to contribute emerging literature on how domestic and international factors interact in shaping the foreign policy preferences of middle powers in this new epoch. Hinging on a synthesis of linkage and regime survival theories, the article argues that as the 'inner-directed linkage' of the West to those authoritarian regimes weakens, those regimes' 'outer-directed linkage' with emerging Asian authoritarian centres strengthens. Having been ruled for more than 20 years by authoritarian leader Erdogan of the JDP (Justice and Development Party), Turkey is an interesting case as an authoritarian middle power with its incrementally intensifying ties with Russia and China. Drawing on the Erdogan regime's statements and acts departing from the liberal order, especially after the Gezi Park protests in 2013 and the failed coup attempt in 2016, the article concludes that Turkey has recalibrated its domestic and foreign policy, replacing its Europhilism with Eurasianism as a part of his regime survival strategy.Area Studie