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Boğaziçi University

UniversityIstanbul, Türkiye

Research output, citation impact, and the most-cited recent papers from Boğaziçi University (Türkiye). Aggregated across the NobleBlocks index of 300M+ scholarly works.

Total works
24.2K
Citations
1.9M
h-index
394
i10-index
27.6K
Also known as
Boğaziçi UniversityBoğaziçi Üniversitesi

Top-cited papers from Boğaziçi University

Survey over image thresholding techniques and quantitative performance evaluation
B. Sankur
2004· Journal of Electronic Imaging4.6Kdoi:10.1117/1.1631315

The <i>Journal of Electronic Imaging</i> (JEI), copublished bimonthly with the Society for Imaging Science and Technology, publishes peer-reviewed papers that cover research and applications in all areas of electronic imaging science and technology.

The ATLAS Experiment at the CERN Large Hadron Collider
G. Aad, E. Abat, J. Abdallah, A. A. Abdelalim +4 more
2008· Journal of Instrumentation4.0Kdoi:10.1088/1748-0221/3/08/s08003

Author(s): Collaboration, The ATLAS; Aad, G; Abat, E; Abdallah, J; Abdelalim, AA; Abdesselam, A; Abdinov, O; Abi, BA; Abolins, M; Abramowicz, H; Acerbi, E; Acharya, BS; Achenbach, R; Ackers, M; Adams, DL; Adamyan, F; Addy, TN; Aderholz, M; Adorisio, C; Adragna, P; Aharrouche, M; Ahlen, SP; Ahles, F; Ahmad, A; Ahmed, H; Aielli, G; Åkesson, PF; Åkesson, TPA; Akimov, AV; Alam, SM; Albert, J; Albrand, S; Aleksa, M; Aleksandrov, IN; Aleppo, M; Alessandria, F; Alexa, C; Alexander, G; Alexopoulos, T; Alimonti, G; Aliyev, M; Allport, PP; Allwood-Spiers, SE; Aloisio, A; Alonso, J; Alves, R; Alviggi, MG; Amako, K; Amaral, P; Amaral, SP; Ambrosini, G; Ambrosio, G; Amelung, C; Ammosov, VV; Amorim, A; Amram, N; Anastopoulos, C; Anderson, B; Anderson, KJ; Anderssen, EC; Andreazza, A; Andrei, V; Andricek, L; Andrieux, M-L; Anduaga, XS; Anghinolfi, F; Antonaki, A; Antonelli, M; Antonelli, S; Apsimon, R; Arabidze, G; Aracena, I; Arai, Y; Arce, ATH; Archambault, JP; Arguin, J-F; Arik, E; Arik, M; Arms, KE; Armstrong, SR; Arnaud, M; Arnault, C; Artamonov, A; Asai, S; Ask, S

Lignocellulosic biomass: a sustainable platform for the production of bio-based chemicals and polymers
Furkan H. Isikgor, C. Remzi Becer
2015· Polymer Chemistry2.6Kdoi:10.1039/c5py00263j

The ongoing research activities in the field of lignocellulosic biomass for production of value-added chemicals and polymers that can be utilized to replace petroleum-based materials are reviewed.

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)<sup>1</sup>
Daniel J. Klionsky, Amal Kamal Abdel‐Aziz, Sara Abdelfatah, Mahmoud Abdellatif +4 more
2021· Autophagy2.6Kdoi:10.1080/15548627.2020.1797280

autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field.

The ATLAS Experiment at the CERN Large Hadron Collider
G. Aad, S. Bentvelsen, G. J. Bobbink, K. Bos +4 more
2008· Research Explorer (The University of Manchester)2.4Kdoi:10.1088/1748-0221/3/08/s08003

The Large Hadron Collider (LHC) at CERN will extend the frontiers of particle physics with its&#13;\nunprecedented high energy and luminosity. Inside the LHC, bunches of up to 1011 protons (p)&#13;\nwill collide 40 million times per second to provide 14 TeV proton-proton collisions at a design&#13;\nluminosity of 1034 cm􀀀2s􀀀1. The LHC will also collide heavy ions (A), in particular lead nuclei, at&#13;\n5.5 TeV per nucleon pair, at a design luminosity of 1027 cm􀀀2s􀀀1.&#13;\nThe high interaction rates, radiation doses, particle multiplicities and energies, as well as the&#13;\nrequirements for precision measurements have set new standards for the design of particle detectors.&#13;\nTwo general purpose detectors, ATLAS (A Toroidal LHC ApparatuS) and CMS (Compact&#13;\nMuon Solenoid) have been built for probing p-p and A-A collisions.&#13;\nThis paper presents a comprehensive overview of the ATLAS detector prior to the first LHC&#13;\ncollisions, written as the installation of the ATLAS detector is nearing completion. This detector&#13;\nrepresents the work of a large collaboration of several thousand physicists, engineers, technicians,&#13;\nand students over a period of fifteen years of dedicated design, development, fabrication, and installation.

GPS constraints on continental deformation in the Africa‐Arabia‐Eurasia continental collision zone and implications for the dynamics of plate interactions
Robert Reilinger, S. McClusky, Philippe Vernant, Shawn Lawrence +4 more
2006· Journal of Geophysical Research Atmospheres2.1Kdoi:10.1029/2005jb004051

The GPS‐derived velocity field (1988–2005) for the zone of interaction of the Arabian, African (Nubian, Somalian), and Eurasian plates indicates counterclockwise rotation of a broad area of the Earth's surface including the Arabian plate, adjacent parts of the Zagros and central Iran, Turkey, and the Aegean/Peloponnesus relative to Eurasia at rates in the range of 20–30 mm/yr. This relatively rapid motion occurs within the framework of the slow‐moving (∼5 mm/yr relative motions) Eurasian, Nubian, and Somalian plates. The circulatory pattern of motion increases in rate toward the Hellenic trench system. We develop an elastic block model to constrain present‐day plate motions (relative Euler vectors), regional deformation within the interplate zone, and slip rates for major faults. Substantial areas of continental lithosphere within the region of plate interaction show coherent motion with internal deformations below ∼1–2 mm/yr, including central and eastern Anatolia (Turkey), the southwestern Aegean/Peloponnesus, the Lesser Caucasus, and Central Iran. Geodetic slip rates for major block‐bounding structures are mostly comparable to geologic rates estimated for the most recent geological period (∼3–5 Myr). We find that the convergence of Arabia with Eurasia is accommodated in large part by lateral transport within the interior part of the collision zone and lithospheric shortening along the Caucasus and Zagros mountain belts around the periphery of the collision zone. In addition, we find that the principal boundary between the westerly moving Anatolian plate and Arabia (East Anatolian fault) is presently characterized by pure left‐lateral strike slip with no fault‐normal convergence. This implies that “extrusion” is not presently inducing westward motion of Anatolia. On the basis of the observed kinematics, we hypothesize that deformation in the Africa‐Arabia‐Eurasia collision zone is driven in large part by rollback of the subducting African lithosphere beneath the Hellenic and Cyprus trenches aided by slab pull on the southeastern side of the subducting Arabian plate along the Makran subduction zone. We further suggest that the separation of Arabia from Africa is a response to plate motions induced by active subduction.

Multiple Kernel Learning Algorithms
Mehmet Gönen, Ethem Alpaydın
20111.7K

In recent years, several methods have been proposed to combine multiple kernels instead of using a single one. These different kernels may correspond to using different notions of similarity or may be using information coming from multiple sources (different representations or different feature subsets). In trying to organize and highlight the similarities and differences between them, we give a taxonomy of and review several multiple kernel learning algorithms. We perform experiments on real data sets for better illustration and comparison of existing algorithms. We see that though there may not be large differences in terms of accuracy, there is difference between them in complexity as given by the number of stored support vectors, the sparsity of the solution as given by the number of used kernels, and training time complexity. We see that overall, using multiple kernels instead of a single one is useful and believe that combining kernels in a nonlinear or data-dependent way seems more promising than linear combination in fusing information provided by simple linear kernels, whereas linear methods are more reasonable when combining complex Gaussian kernels.

Consensus statement for stability assessment and reporting for perovskite photovoltaics based on ISOS procedures
Mark Khenkin, Eugene A. Katz, Antonio Abate, Giorgio Bardizza +4 more
2020· Nature Energy1.7Kdoi:10.1038/s41560-019-0529-5

Abstract Improving the long-term stability of perovskite solar cells is critical to the deployment of this technology. Despite the great emphasis laid on stability-related investigations, publications lack consistency in experimental procedures and parameters reported. It is therefore challenging to reproduce and compare results and thereby develop a deep understanding of degradation mechanisms. Here, we report a consensus between researchers in the field on procedures for testing perovskite solar cell stability, which are based on the International Summit on Organic Photovoltaic Stability (ISOS) protocols. We propose additional procedures to account for properties specific to PSCs such as ion redistribution under electric fields, reversible degradation and to distinguish ambient-induced degradation from other stress factors. These protocols are not intended as a replacement of the existing qualification standards, but rather they aim to unify the stability assessment and to understand failure modes. Finally, we identify key procedural information which we suggest reporting in publications to improve reproducibility and enable large data set analysis.

DeepDTA: deep drug–target binding affinity prediction
Hakime Öztürk, Arzucan Özgür, Elif Özkırımlı
2018· Bioinformatics1.6Kdoi:10.1093/bioinformatics/bty593

Motivation: The identification of novel drug-target (DT) interactions is a substantial part of the drug discovery process. Most of the computational methods that have been proposed to predict DT interactions have focused on binary classification, where the goal is to determine whether a DT pair interacts or not. However, protein-ligand interactions assume a continuum of binding strength values, also called binding affinity and predicting this value still remains a challenge. The increase in the affinity data available in DT knowledge-bases allows the use of advanced learning techniques such as deep learning architectures in the prediction of binding affinities. In this study, we propose a deep-learning based model that uses only sequence information of both targets and drugs to predict DT interaction binding affinities. The few studies that focus on DT binding affinity prediction use either 3D structures of protein-ligand complexes or 2D features of compounds. One novel approach used in this work is the modeling of protein sequences and compound 1D representations with convolutional neural networks (CNNs). Results: The results show that the proposed deep learning based model that uses the 1D representations of targets and drugs is an effective approach for drug target binding affinity prediction. The model in which high-level representations of a drug and a target are constructed via CNNs achieved the best Concordance Index (CI) performance in one of our larger benchmark datasets, outperforming the KronRLS algorithm and SimBoost, a state-of-the-art method for DT binding affinity prediction. Availability and implementation: https://github.com/hkmztrk/DeepDTA. Supplementary information: Supplementary data are available at Bioinformatics online.

Formal aspects of model validity and validation in system dynamics
Yaman Barlas
1996· System Dynamics Review1.5Kdoi:10.1002/(sici)1099-1727(199623)12:3<183::aid-sdr103>3.0.co;2-4

Model validation constitutes a very important step in system dynamics methodology. Yet, both published and informal evidence indicates that there has been little effort in system dynamics community explicitly devoted to model validity and validation. Validation is a prolonged and complicated process, involving both formal/quantitative tools and informal/qualitative ones. This paper focuses on the formal aspects of validation and presents a taxonomy of various aspects and steps of formal model validation. First, there is a very brief discussion of the philosophical issues involved in model validation, followed by a flowchart that describes the logical sequence in which various validation activities must be carried out. The crucial nature of structure validity in system dynamics (causal-descriptive) models is emphasized. Then examples are given of specific validity tests used in each of the three major stages of model validation: Structural tests, structure-oriented behavior tests and behavior pattern tests. Also discussed is if and to what extent statistical significance tests can be used in model validation. Among the three validation stages, the special importance of structure-oriented behavior tests is emphasized. These are strong behavior tests that can provide information on potential structure flaws. Since structure-oriented behavior tests combine the strength of structural orientation with the advantage of being quantifiable, they seem to be the most promising direction for research on model validation.

Pharmaceutical pollution of the world’s rivers
John L. Wilkinson, Alistair B.A. Boxall, Dana W. Kolpin, Kmy Leung +4 more
2022· Proceedings of the National Academy of Sciences1.5Kdoi:10.1073/pnas.2113947119

Environmental exposure to active pharmaceutical ingredients (APIs) can have negative effects on the health of ecosystems and humans. While numerous studies have monitored APIs in rivers, these employ different analytical methods, measure different APIs, and have ignored many of the countries of the world. This makes it difficult to quantify the scale of the problem from a global perspective. Furthermore, comparison of the existing data, generated for different studies/regions/continents, is challenging due to the vast differences between the analytical methodologies employed. Here, we present a global-scale study of API pollution in 258 of the world's rivers, representing the environmental influence of 471.4 million people across 137 geographic regions. Samples were obtained from 1,052 locations in 104 countries (representing all continents and 36 countries not previously studied for API contamination) and analyzed for 61 APIs. Highest cumulative API concentrations were observed in sub-Saharan Africa, south Asia, and South America. The most contaminated sites were in low- to middle-income countries and were associated with areas with poor wastewater and waste management infrastructure and pharmaceutical manufacturing. The most frequently detected APIs were carbamazepine, metformin, and caffeine (a compound also arising from lifestyle use), which were detected at over half of the sites monitored. Concentrations of at least one API at 25.7% of the sampling sites were greater than concentrations considered safe for aquatic organisms, or which are of concern in terms of selection for antimicrobial resistance. Therefore, pharmaceutical pollution poses a global threat to environmental and human health, as well as to delivery of the United Nations Sustainable Development Goals.

The NANOGrav 15 yr Data Set: Evidence for a Gravitational-wave Background
Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald, Zaven Arzoumanian +4 more
2023· The Astrophysical Journal Letters1.4Kdoi:10.3847/2041-8213/acdac6

Abstract We report multiple lines of evidence for a stochastic signal that is correlated among 67 pulsars from the 15 yr pulsar timing data set collected by the North American Nanohertz Observatory for Gravitational Waves. The correlations follow the Hellings–Downs pattern expected for a stochastic gravitational-wave background. The presence of such a gravitational-wave background with a power-law spectrum is favored over a model with only independent pulsar noises with a Bayes factor in excess of 10 14 , and this same model is favored over an uncorrelated common power-law spectrum model with Bayes factors of 200–1000, depending on spectral modeling choices. We have built a statistical background distribution for the latter Bayes factors using a method that removes interpulsar correlations from our data set, finding p = 10 −3 (≈3 σ ) for the observed Bayes factors in the null no-correlation scenario. A frequentist test statistic built directly as a weighted sum of interpulsar correlations yields p = 5 × 10 −5 to 1.9 × 10 −4 (≈3.5 σ –4 σ ). Assuming a fiducial f −2/3 characteristic strain spectrum, as appropriate for an ensemble of binary supermassive black hole inspirals, the strain amplitude is <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mn>2.4</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.6</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.7</mml:mn> </mml:mrow> </mml:msubsup> <mml:mo>×</mml:mo> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>15</mml:mn> </mml:mrow> </mml:msup> </mml:math> (median + 90% credible interval) at a reference frequency of 1 yr −1 . The inferred gravitational-wave background amplitude and spectrum are consistent with astrophysical expectations for a signal from a population of supermassive black hole binaries, although more exotic cosmological and astrophysical sources cannot be excluded. The observation of Hellings–Downs correlations points to the gravitational-wave origin of this signal.

Understanding English as a Lingua Franca
Cem Alptekin
2012· ELT Journal1.4Kdoi:10.1093/elt/ccs004

In Understanding English as a Lingua Franca, Barbara Seidlhofer deals with the linguistic implications of globalization in the Expanding Circle (Kachru 1992) viewed from a transformationalist perspective, as opposed to one that is hyperglobalist. As such, globalization is taken as the driving force behind social, economic, and political changes in the local setting, often to the benefit of its inhabitants. It need not be seen as the imposition of the global on to the local, leading to linguistic imperialism and cultural homogenization in the way hyperglobalists tend to view it (for example Phillipson 1992). From a transformationalist viewpoint, English is perceived as an international medium of interconnectedness (Dewey 2007) between the global and the local (or the centre and the periphery), leading to plurality in norms and approaches. In its new, unique, and unprecedented role, English, according to Seidlhofer, has thus become ‘both a result and a reinforcement’ of globalization and ‘naturally gets transformed accordingly’ (p. 83). It follows that a new sociolinguistic conceptualization of the language is warranted, one which should strip it of its native ‘ownership’ (Widdowson 1994) and of the control such ownership exercises (both explicitly and implicitly) on its international development. Such control is ironic, if not paradoxical, in view of the world’s NNS to NS ratio being approximately three to one according to conservative estimates. After all, as Jenkins (2003: 44) indicates, if, as a global language, English has become the language of ‘others’, it is natural that the ‘others’ should have the right to innovate. Their innovations cannot be automatically labelled ‘wrong’ by NSs.

Combined Measurement of the Higgs Boson Mass in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>p</mml:mi><mml:mi>p</mml:mi></mml:math>Collisions at<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>=</mml:mo><mml:mn>7</mml:mn></mml:math>and 8 TeV with the ATLAS and CMS Experiments
G. Aad, B. Abbott, J. Abdallah, O. Abdinov +4 more
2015· Physical Review Letters1.3Kdoi:10.1103/physrevlett.114.191803

A measurement of the Higgs boson mass is presented based on the combined data samples of the ATLAS and CMS experiments at the CERN LHC in the H→γγ and H→ZZ→4ℓ decay channels. The results are obtained from a simultaneous fit to the reconstructed invariant mass peaks in the two channels and for the two experiments. The measured masses from the individual channels and the two experiments are found to be consistent among themselves. The combined measured mass of the Higgs boson is m_{H}=125.09±0.21 (stat)±0.11 (syst) GeV.

MAC protocols for wireless sensor networks: a survey
Ilker Demirkol, Cem Ersoy, Fatih Alagöz
2006· IEEE Communications Magazine1.2Kdoi:10.1109/mcom.2006.1632658

Wireless sensor networks are appealing to researchers due to their wide range of application potential in areas such as target detection and tracking, environmental monitoring, industrial process monitoring, and tactical systems. However, low sensing ranges result in dense networks and thus it becomes necessary to achieve an efficient medium-access protocol subject to power constraints. Various medium-access control (MAC) protocols with different objectives have been proposed for wireless sensor networks. In this article, we first outline the sensor network properties that are crucial for the design of MAC layer protocols. Then, we describe several MAC protocols proposed for sensor networks, emphasizing their strengths and weaknesses. Finally, we point out open research issues with regard to MAC layer design.

Measurements of the Higgs boson production and decay rates and constraints on its couplings from a combined ATLAS and CMS analysis of the LHC pp collision data at s = 7 $$ \sqrt{s}=7 $$ and 8 TeV
G. Aad, B. Abbott, J. Abdallah, O. Abdinov +4 more
2016· Journal of High Energy Physics1.1Kdoi:10.1007/jhep08(2016)045

Combined ATLAS and CMS measurements of the Higgs boson production and decay rates, as well as constraints on its couplings to vector bosons and fermions, are presented. The combination is based on the analysis of five production processes, namely gluon fusion, vector boson fusion, and associated production with a W or a Z boson or a pair of top quarks, and of the six decay modes H → ZZ, W W , γγ, ττ, bb, and μμ. All results are reported assuming a value of 125.09 GeV for the Higgs boson mass, the result of the combined measurement by the ATLAS and CMS experiments. The analysis uses the CERN LHC proton-proton collision data recorded by the ATLAS and CMS experiments in 2011 and 2012, corresponding to integrated luminosities per experiment of approximately 5 fb$^{−1}$ at $\sqrt{s}$=7 TeV and 20 fb−1 at $\sqrt{s}$=8 TeV. The Higgs boson production and decay rates measured by the two experiments are combined within the context of three generic parameterisations: two based on cross sections and branching fractions, and one on ratios of coupling modifiers. Several interpretations of the measurements with more model-dependent parameterisations are also given. The combined signal yield relative to the Standard Model prediction is measured to be 1.09 ± 0.11. The combined measurements lead to observed significances for the vector boson fusion production process and for the H → ττ decay of 5.4 and 5.5 standard deviations, respectively. The data are consistent with the Standard Model predictions for all parameterisations considered.

Network-Induced Constraints in Networked Control Systems—A Survey
Lixian Zhang, Huijun Gao, Okyay Kaynak
2012· IEEE Transactions on Industrial Informatics1.1Kdoi:10.1109/tii.2012.2219540

Networked control systems (NCSs) have, in recent years, brought many innovative impacts to control systems. However, great challenges are also met due to the network-induced imperfections. Such network-induced imperfections are handled as various constraints, which should appropriately be considered in the analysis and design of NCSs. In this paper, the main methodologies suggested in the literature to cope with typical network-induced constraints, namely time delays, packet losses and disorder, time-varying transmission intervals, competition of multiple nodes accessing networks, and data quantization are surveyed; the constraints suggested in the literature on the first two types of constraints are updated in different categorizing ways; and those on the latter three types of constraints are extended.

Data-Based Techniques Focused on Modern Industry: An Overview
Shen Yin, Xianwei Li, Huijun Gao, Okyay Kaynak
2014· IEEE Transactions on Industrial Electronics993doi:10.1109/tie.2014.2308133

This paper provides an overview of the recent developments in data-based techniques focused on modern industrial applications. As one of the hottest research topics for complicated processes, the data-based techniques have been rapidly developed over the past two decades and widely used in numerous industrial sectors nowadays. The core of data-based techniques is to take full advantage of the huge amounts of available process data, aiming to acquire the useful information within. Compared with the well-developed model-based approaches, data-based techniques provide efficient alternative solutions for different industrial issues under various operating conditions. The main objective of this paper is to review and summarize the recent achievements in data-based techniques, especially for complicated industrial applications, thus providing a referee for further study on the related topics both from academic and practical points of view. This paper begins with a brief evolutionary overview of data-based techniques in the last two decades. Then, the methodologies only based on process measurements and the model-data integrated techniques will be further introduced. The recent developments for modern industrial applications are, respectively, presented mainly from perspectives of monitoring and control. The new trends of data-based technique as well as potential application fields are finally discussed.

Particle-flow reconstruction and global event description with the CMS detector
A. M. Sirunyan, A. Tumasyan, W. Adam, E. Asilar +4 more
2017· Journal of Instrumentation979doi:10.1088/1748-0221/12/10/p10003

The CMS apparatus was identified, a few years before the start of the LHC operation at CERN, to feature properties well suited to particle-flow (PF) reconstruction: a highly-segmented tracker, a fine-grained electromagnetic calorimeter, a hermetic hadron calorimeter, a strong magnetic field, and an excellent muon spectrometer. A fully-fledged PF reconstruction algorithm tuned to the CMS detector was therefore developed and has been consistently used in physics analyses for the first time at a hadron collider. For each collision, the comprehensive list of final-state particles identified and reconstructed by the algorithm provides a global event description that leads to unprecedented CMS performance for jet and hadronic decay reconstruction, missing transverse momentum determination, and electron and muon identification. This approach also allows particles from pileup interactions to be identified and enables efficient pileup mitigation methods. The data collected by CMS at a centre-of-mass energy of 8show excellent agreement with the simulation and confirm the superior PF performance at least up to an average of 20 pileup interactions.

FCC-ee: The Lepton Collider
Asmâa Abada, M. Abbrescia, Shehu AbdusSalam, I. M. Abdyukhanov +4 more
2019· The European Physical Journal Special Topics904doi:10.1140/epjst/e2019-900045-4

In response to the 2013 Update of the European Strategy for Particle Physics, the Future Circular Collider (FCC) study was launched, as an international collaboration hosted by CERN. This study covers a highest-luminosity high-energy lepton collider (FCC-ee) and an energy-frontier hadron collider (FCC-hh), which could, successively, be installed in the same 100 km tunnel. The scientific capabilities of the integrated FCC programme would serve the worldwide community throughout the 21st century. The FCC study also investigates an LHC energy upgrade, using FCC-hh technology. This document constitutes the second volume of the FCC Conceptual Design Report, devoted to the electron-positron collider FCC-ee. After summarizing the physics discovery opportunities, it presents the accelerator design, performance reach, a staged operation scenario, the underlying technologies, civil engineering, technical infrastructure, and an implementation plan. FCC-ee can be built with today's technology. Most of the FCC-ee infrastructure could be reused for FCC-hh. Combining concepts from past and present lepton colliders and adding a few novel elements, the FCC-ee design promises outstandingly high luminosity. This will make the FCC-ee a unique precision instrument to study the heaviest known particles (Z, W and H bosons and the top quark), offering great direct and indirect sensitivity to new physics.