bluuebunny/crossref_metadata_2025 huggingface dataset:
Understanding human–water feedbacks of interventions in agricultural systems with agent based models: a review
Authors: Alam Mohammad Faiz , McClain Michael , Sikka Alok , Pande Saket
Published: September 2022

Increased variability of the water cycle manifested by climate change is a growing global threat to agriculture with strong implications for food and livelihood security. Thus, there is an urgent need for adaptation in agriculture. Agricultural water management (AWM) interventions, interventions for managing water supply and demand, are extensively promoted and implemented as adaptation measures in multiple development programs globally. Studies assessing these adaptation measures overwhelmingly focus on positive impacts, however, there is a concern that these studies may be biased towards well-managed and successful projects and often miss out on reporting negative externalities. These externalities result from coevolutionary dynamics of human–water systems as AWM interventions impact hydrological flows and their use and adoption is shaped by the societal response. We review the documented externalities of AWM interventions and present a conceptual framework classifying negative externalities linked to water and human systems into negative hydrological externalities and unexpected societal feedbacks. We show that these externalities can lead to long term unsustainable and inequitable outcomes. Understanding how the externalities lead to undesirable outcomes demands rigorous modeling of the feedbacks between human and water systems, for which we discuss the key criteria that such models should meet. Based on these criteria, we showcase that differentiated and limited inclusion of key feedbacks in current water modeling approaches (e.g. hydrological models, hydro-economic, and water resource models) is a critical limitation and bottleneck to understanding and predicting negative externalities of AWM interventions. To account for the key feedback, we find agent-based modeling (ABM) as the method that has the potential to meet the key criteria. Yet there are gaps that need to be addressed in the context of ABM as a tool to unravel the negative externalities of AWM interventions. We carry out a systemic review of ABM application to agricultural systems, capturing how it is currently being applied and identifying the knowledge gaps that need to be bridged to unravel the negative externalities of AWM interventions. We find that ABM has been extensively used to model agricultural systems and, in many cases, the resulting externalities with unsustainable and inequitable outcomes. However, gaps remain in terms of limited use of integrated surface–groundwater hydrological models, inadequate representation of farmers’ behavior with heavy reliance on rational choice or simple heuristics and ignoring heterogeneity of farmers’ characteristics within a population.
The spatiotemporal trajectory of US agricultural irrigation withdrawal during 1981–2015
Authors: Zeng Ruijie , Ren Weiwei
Published: September 2022

Irrigation has enhanced food security and biofuel production throughout the world. However, the sustainability of irrigation faces challenges from climate variability and extremes, increasing consumption from irrigated cropland expansion, and competing demands from other water use sectors. In this study, we investigated the agricultural water withdrawal landscape of the contiguous United States (CONUS) over 1981–2015, assessed its spatial and temporal changes, and analyzed the factors driving the changes. We introduced the concept of ‘center of mass’ to calculate the spatiotemporal trajectory of water withdrawal, along with climatic and agricultural factors at state, regional and CONUS scales. At the CONUS level, the total agricultural water withdrawal has decreased during 1981–2015, and the centroid of water withdrawal consistently moved toward the east, caused by reduced water withdrawal in the western states and increased withdrawal in the eastern states. While the CONUS irrigation trajectory is not mainly affected by climatologic trends, extreme drought conditions (e.g. the mega droughts in western states since 2000) may interrupt the trend. In the Western US, irrigation withdrawal reduction was mainly achieved by adoption of high-efficiency irrigation technology, while the irrigated acreage remains relatively stable. Under drought conditions, irrigation withdrawal often switched from surface water to groundwater sources, posing challenges on groundwater sustainability under prolonged drought conditions. The Eastern US has experienced accelerating agricultural withdrawal from both surface water and groundwater sources. This was mainly driven by expansion in irrigated acreage in the Midwest and lower Mississippi River, with irrigated croplands supplied by mixed flood irrigation and high-efficiency irrigation methods. At the state level, some states exhibited discrepancy in agricultural withdrawal centroids from surface water and groundwater sources, as results of climate heterogeneity, water availability and infrastructure development. This study provides understanding of the driving forces in the spatiotemporal trends of CONUS agricultural water withdrawal in different regions and implications for predicting future agricultural withdrawal under changing climatic and socioeconomic uncertainties.
On the Pasternack–Sternheimer theorem for bound states in hydrogenic atoms and ions derived by operator calculus
Authors: Hey J D
Published: September 2022

The Pasternack–Sternheimer theorem for bound states (Pasternack and Sternheimer 1962 J. Math. Phys.
3 1280) is obtained directly by the methods of operator calculus set out earlier (Hey 2006 J. Phys. B: At. Mol. Phys.
39 2641–64), on the basis of the factorisation technique of Infeld and Hull (Infeld and Hull 1951 Rev. Mod. Phys.
23 21–68). The present derivation, which complements the group theoretical treatments of Armstrong (Armstrong 1970 J. Phys. Colloq.
31 C4-17–23) and Cunningham (Cunningham 1972 J. Math. Phys. 13 33–9), not only elucidates the original result in terms of fundamental quantum mechanical theory, but also reveals some apparently new inter-connections between different radial matrix elements (for given n, diagonal and off-diagonal in ℓ, ℓ′) of hydrogenic atoms and ions. The key equation used to derive the theorem here is shown to follow identically in the non-relativistic limit from the treatment of the generalised Kepler problem by Crubellier and Feneuille (Crubellier and Feneuille 1971 J. Physique
32 405–11). This work is a continuation of studies employing operator methods to provide results of potential usefulness for spectroscopic studies of laboratory and astrophysical plasmas, in particular to transitions between states of high principal quantum number, as in the high-n radio recombination lines (Hey 2013 J. Phys. B: At. Mol. Opt. Phys.
46 175702; Peach 2014 Adv. Space Res.
54 1180-83).
Green Productivity Approach in Batik Industry
Authors: Shofari F D , Kurniawati D A , Paramawardhani H
Published: September 2022

Nowadays, Industries compete one to each other on many factors. When industries improve productivity, they may ignore the environmental effect. Green Productivity is a concept that can improve both productivity and environmental performance. Thus, this research was conducted in the batik industry namely Batik Ayu Arimbi. The Batik industry is known as one of the most polluting industries since it creates both liquid and solid waste. Most of them release the waste directly into nature without disposing it in a proper way. After the EPI index has been calculated, it is known that the environmental performance of this industry is far below the government standards. To tackle the issue, this research uses the green productivity approach. This approach results in 2 (two) alternatives solutions for Batik production which increased the productivity as well as the EPI index.
Ecotourism in a Hazardous Small-Volcanic Island: Tidore Island, Indonesia
Authors: Wijayanti H , Marfai M A , Mutaqin B W , Hadmoko D S , Lavigne F , Faral A , Riasasi W
Published: September 2022

Being known as a small island with the highest volcano in North Maluku Province, Tidore Island is also famed for its exotic ecotourism potential. There are many benefits for areas that have good ecotourism potential, but it is necessary to consider the potential for local disasters. Kie Matubu Volcano is currently in a dormant status and is likely to be active at any time. Regional planning and disaster mitigation should thus go hand in hand, but the complexity of the geographical conditions of a small island requires various prior analyses. This research aims to integrate ecotourism mentioned in Regional Planning with disaster mitigation action in Tidore Island. Combining spatial analysis and social vulnerability can provide an overview of the integration planning and disaster management in this small volcanic island to improve community resilience. However, it still calls for some actions to develop ecotourism areas that co-occur with disaster mitigation efforts. Several villages with high social vulnerability in the western, southern, and eastern parts of the island require additional infrastructures (e.g., port terminals) and functional disaster evacuation facilities as the important aspect while disaster occurs.
Evaluation of blocking area management based on ecological and socio-economic sensitivity mapping in Sermo Wildlife Sanctuary, Kulon Progo, Yogyakarta
Authors: Damayanti N. , Marhaento H. , Poedjirahajoe E.
Published: September 2022

Sermo Wildlife Sanctuary (SWS) is a nature reserve area located in Kulon Progo, Yogyakarta that has a unique diversity of plant and animal species. SWS was established in 2014 with a total of 184,99 ha area based on the Decree of the Ministry of Forestry No. 3112/Menhut-VII/KUH/2014. The area management in SWS is managed by a blocking system that since 2016 has not been evaluated. This study aims to evaluate the blocking area in SWS based on the current ecological and socio-economy sensitivity in SWS. We carried out Spatial Multi Criteria Analysis (SMCA) that used scores and weights to each ecological and socio-economic criterion and sub-criteria. For the ecological sensitivity, four criteria were used such as slope, land cover, canopy density, and the potential presence of protected wildlife. While for the socio-economic sensitivity, four criteria were used such as accessibility, tourism area, built facilities, and water-use infrastructure. In addition, participatory mapping was carried out to map the activities from the local communities inside the SWS. Based on the results, we propose a larger special block and rehabilitation block than before in 2016, because there was expansion in the built facilities and open area inside the SWS.
Predicting material consumption in a Circular Economy oriented design methodology for pedestrian and cycling bridges
Authors: Anastasiades K , Audenaert A , Blom J
Published: September 2022

A Circular Economy (CE) oriented design methodology for pedestrian and cycling bridges that takes the 4Rs of the CE -Reduce, Reuse, Recycle, Recover- as basis needs to be developed. The first R, Reduce, is mostly neglected, even though it is the most important R in the CE. Nevertheless, a CE oriented design methodology also needs to consider and formalise Reduce. It is proposed to do this by measuring the material efficiency of a structure. Therefore, a reference volume of material needs to be found. This paper proposes a methodology to predict the necessary amount of material needed for the bridge structure. The methodology takes the theory of the morphological indicators as basis. Morphological indicators are used in the conceptual design phase to find the most efficient structural typology and global dimensions. However, it was found that the volume indication that results from these morphological indicators is not realistic. The main reasons are that they consider a fully stressed state for each component, and they do not consider standard profile sections. Therefore, two correction curves are proposed to correct the volume obtained from the morphological indicators into a realistic one. The limitations of this study are that it only focusses on Warren truss bridges and only considers vertical service loads. Further research will have to focus on incorporating other types of trusses and other structural typologies like arched, suspension and cable-stayed bridges. In addition, more loads like wind and snow that can act on bridges need to be considered.
BTPFlux: a building material flow analysis model to enhance the urban metabolism on French territories
Authors: Sorin E , Tirado R , Gully E , Louërat M , Laurenceau S
Published: September 2022

Worldwide, the construction sector is the principal consumer of raw resources (50% of the natural resources) and the leading producer of solid waste (2.2 billion tons per year). Because of their quantity and their potential for development, construction wastes constitute a catalyst for establishing strategies and action programs aimed at making the management of resources circular at several territorial scales. Performing these strategies needs a detailed and structured knowledge of flows. In this context, the CSTB has developed a macro-component bottom-up-based model: BTPFlux, that aims to characterize the materiality of the building stock and the associated demolition, and renovation waste flows. A national database with generic information for every building on the metropolitan French territory was used. This database gathers information such as the surface, the typology, or the year of construction of the buildings and is then linked with a specific database characterizing existing construction products. This method provides a detailed characterization of the building material stock available on the French metropolitan territory. So, the environmental impacts, the treatment costs, and the valorisation potentials can be estimated by implementing different management scenarios for each category of waste assessed. The model was already successfully applied to the “Ile de France” region and can be replicated to any other French territory. The results will allow the stakeholders to better understand the materiality of their territory, giving them the possibility of making optimal decisions to implement the reuse and recycling of secondary resources. However, some improvements can still be made in the description levels of macrocomponents or in the description of infrastructures that BTPFlux does not currently model.
Climate impacts of wood/ timber as a building material – investigated on three urban quarters in Germany (CIW)
Authors: Roswag-Klinge E , Neumann E , Klinge A
Published: September 2022

Due to the current discussion about the shortage of resources and the excess of greenhouse gas emissions, timber construction is experiencing a renaissance in Germany. As a renewable resource, wood can replace emission-intensive building materials and, if left long-term in the construction, lead to negative balances, i.e. carbon sinks at the construction phase (LCA phase A1-A3). This means that more carbon could be stored in the construction than is emitted during production. This study analyses different buildings ranging from row houses to high-rise buildings that are envisioned as envisioned as envisioned as envisioned as envisioned as timber construction of three so called timber-quarters (Holzbauquartiere). For all buildings, the current design/ construction, a conventional as well as a timber+ construction (maximum possible timber use in construction) variant have been evaluated. The calculations were conducted with eLCA the LCA tool of the Bewertungssystem Nachhaltiges Bauen (BNB) (German Green Building System) and the data sets of the German ÖKOBAUDAT[11]. The results are given per m2 gross floor area per user, per building and per neighbourhood. The investigations show the importance of the material choice regarding the climate gas emissions of the buildings and how large the proportion of wood must be in order to design the building envelope (KG 300 (cost group for architectural elements) in a climate gas neutral way. Planning parameters for a climate gas neutral design and construction of buildings are derived from the analysis.
CircularWOOD – Towards Circularity in Timber Construction in the German Context
Authors: Schuster S , Geier S
Published: September 2022

The circular economy can pave the way to achieve ambitious sustainability goals. A major perpetrator of resource and material waste is the building sector. A lot of research results already provide innovative technologies and solutions for circular construction. However, what many of the circular economy initiatives in the construction sector have in common, is a certain malaise in moving from pilot projects with high individual engagement to actions on a larger scale. Prefabricated timber construction is one of the most promising key technologies towards a more resource efficient Europe. Despite this potential, downcycling or an early thermic utilization is common practice. Valuable resources are wasted and already captured CO2 is released. The research project circularWOOD aims to provide a better understanding for potentials and barriers in a first step. This paper outlines first findings. Prefabrication and element design facilitate circular construction approaches. The context in which stakeholder implement circular construction approaches is widened. A wide range of economic and ecological aspects is supplemented with cultural, political, and regulatory conditions. Under the premise of reuse with a minimum of necessary adaptation structural aspects are evaluated. The results show a current concentration on new construction with easy-to-implement design approaches. Further efforts towards strategies for the reuse of existing construction and experiences to facilitate the diffusion within the timber construction sector are required.
Suggestions for solution space exploration in the early stage of architectural design based on a literature review
Authors: Li J , Bi X , Yang W
Published: September 2022

Early design decisions have higher potential to influence building performance compared with the decisions made at later design stages. Performance simulation and optimization algorithms have been integrated to assist early design in reducing carbon emissions, improving indoor thermal comfort, etc. However, early decision making within a limited time frame is still challenging due to the large number of design options, the lack of decision-making guidance, and the trade-offs among various requirements. Selecting appropriate methods to explore design space is the key to find an ideal solution. This paper reviewed the challenges and identified the key questions to access the ability of existing decision-making methods to cope with different challenges. It is concluded that the interactive exploration of design space could be more effective and efficient by (1) combining the surrogate models and the automated optimization algorithms to improve the efficiency of the building performance calculation and the optimal design space position; and by (2) extending the optimal design space to increase the solution diversity, and (3) filtering the near optimal design space with consideration of the stakeholders’ preferences and values. Further integration of tools for building performance simulation, diversity description and decision-making guidance is needed to support the decision -making process.
Reviewing allocation approaches and modelling in LCA for building refurbishment
Authors: Kjær Zimmermann R , Nygaard Rasmussen F , Kanafani K , Malabi Eberhardt L C , Birgisdóttir H
Published: September 2022

With a growing building stock and initiatives such as the European “renovation wave” which aims to double the annual energy renovation rates in the next ten years, environmental assessment of building refurbishment becomes still more important. Using standardized environmental assessment methods such as life cycle assessment (LCA) on renovation projects is important to keep impacts low, and avoid burden shifting. However, a specific methodological challenge in refurbishment projects is how to include the existing building materials in the assessment. The aim of this study is therefore to present and characterise different existing allocation approaches for LCA in refurbishments. Furthermore, the study highlights advantages and disadvantages of the analysed approaches from an LCA practitioner’s view. A literature review was conducted to find studies that illustrate the different allocation approaches and modelling of the existing materials in refurbishment projects. The approaches characterised in the study include allocation using 50:50, avoided burden, product environmental footprint (PEF), burden-free (and semi-burden-free), residual value or depreciation, and adjusting for past production of existing materials. The implications for LCA-practitioners were evaluated based on the work burden required for application. Here, the main cons relate to the large workload connected to modelling the existing building.
Automated Life cycle inventories for existing buildings – a parametric reference model approach
Authors: Kanafani K , Garnow A , Zimmermann R , Sørensen C , Stapel E , Birgisdottir H
Published: September 2022

Buildings account for 40% of global Greenhouse gas (GHG) emissions. In heating-dominated climates, most building-related emissions originate from building stock operational energy, especially from buildings constructed before energy requirements were introduced. Renovation can mitigate operational emissions, however, materials should be included to increase the mitigation potential. Life-cycle assessment (LCA) includes emissions from materials and energy but are time-consuming in renovations because BIM-aided approaches for automating inventories are inaccessible for existing building fabric. This paper proposes a parametric inventory-generator for existing buildings, which defines material quantities through few key variables, which are accessible in early design stages, and which relate to a reference model for a specific building type. The generated model includes LCA inventory data such as service life, replacements, and End of Life from a generic impacts database. The model is adjustable and can be supplied with predefined renovation interventions and new components. The proposed simplification has potential to facilitate modelling of LCA inventories for every existing building, and makes LCA feasible for more than deep renovations, offering a base for the proposed renovation pass by the EU commission. Future research will add building types and explore implementing default inventories based on cadastre data as public resource.
Bridging the gap – A database tool for BIM-based circularity assessment
Authors: Göswein V , Carvalho S , Lorena A , Fernandes J , Ferrão P
Published: September 2022

The concept of circular economy attracts attention across sectors. Since construction materials are the single largest material stock and flow, there is a particular interest from research and policy to apply the circularity concept to buildings. Large quantities of construction and demolition waste end up in landfill, despite new EU legislation that requires a 70% recovery rate. There is a gap between this ambitious goal and the reality of the construction industry. Building Information Modelling (BIM) has the potential to improve building design and construction processes for an increased recovery of materials. However, insufficient data, inconsistent methods and interoperability issues inhibit BIM application to unfold its full potential in circularity assessments. This paper introduces the CirBIM database framework. It provides BIM users with the required robust data to improve the circularity throughout the building’s life cycle: from the design phase throughout renovation activities to the end-of-life stage. The paper proposes a new workflow of building circularity assessment, describe the architecture of the new database tool, and recommends relevant data sources and information models to streamline data mining processes. The new database tool is exemplified through application to a case study building in Portugal, emphasizing the need for different metrics and the need of integration of the end-of-life scenarios in the building design stage.
Circularity of building materials: A non-discriminating calculation methodology
Authors: Rovers R
Published: September 2022

The energy transition has shifted impacts to materials, their energy use and potential depletion. Especially affected is the building and construction sector, since it is the sector which has the largest consumption of materials. Therefore, it is of utmost importance that materials cycles be closed as well, that they stay within system boundaries, and that we use objective calculation and evaluation methods. If we look at organic or biobased resources, the basic impacts in their flow are obvious and can be characterised fairly simply: they grow on the basis of solar energy at a certain speed and volume per unit of land. It’s a constantly renewing flow, with use maximised to what naturally (re-)grows. In-depth analyses have created growing awareness that non-organic materials are also in fact renewable, even without human intervention but in different scales of time and volume, in time frames way beyond the normal planning horizons of humans. They are renewed by volcanic and tectonic movements of the Earth’s crust. The paper explores how non organic materials will renew, that is, become re-concentrated in the Earth’s crust. In fact it is the concentration that is crucial for effective use, without additional energy input that would deplete other sources. From this analysis it follows that all resources can be characterised by the speed and volume in which they concentrate—either by the soil and solar route, or by the Earth movement route. : “Resources can thus be grouped into four categories: regrowable, streaming, slow and synthetic. The characterisation shows a similar pattern in other indicators for these resources: the slower the resources are regenerated, the more (embodied) energy required to obtain the resources, for instance. This is an attempt, a pre-study, to set up a methodology, and the first estimations for the global flows of resources in different categories. In the end it turns out that all resources have a natural renewal basis, and that there are no sustainable or non-sustainable (or non-renewable) resources: it is their use, within maximised flows, that determines their sustainability. It requires that we re-define the notion of ‘circular’.
Development of a new environmental scoring methodology for building products, a French case study
Authors: Bahrar M , Jusselme T
Published: September 2022

The building sector consumes about one-third of total final energy and contributes to 38% of greenhouse gas (GHG) emissions around the world. Thus, the EU has established a set of directives that includes the EPBD and the EED to achieve carbon neutrality by 2050. Hence, France adopted more challenging legislation by introducing the new environmental regulation RE2020. Among other measures, the RE2020 allocates a carbon budget to new housings starting from 2022. As a consequence, it promotes the use of materials and products that have a lower environmental impact. In this low carbon material competition, one of the challenges is related to the comparability of environmental product declarations (EPDs) and the lack of harmonization in terms of functional units and lifespan. Also, EPDs have multiple impact categories that make the decision-making process complex. In this context, the objective of this research is to develop a new environmental scoring methodology for building products based on their life cycle assessment. The methodology has been applied to two product families: windows and insulation as case studies thanks to the French EPD database called INIES.
The Impact of Covid-19 Pandemic towards the Resilience of Small Medium Enterprises (SMEs) in Malaysia
Authors: Rashid M F , Yusoff N S , Kamarudin K H
Published: September 2022

The Covid-19 pandemic has impacted the entire world dramatically. The unprecedented Covid-19 pandemic has widely impacted on Malaysia’s economy, especially towards the small-scale economic activities related to the small medium enterprises (SMEs). Therefore, this paper aims to determine the impact of the Covid-19 pandemic towards the resilience of SMEs in Johor, Malaysia. The research methodology employed a quantitative method through a survey method via questionnaire sampling of 60 owners involved in SMEs operators across the case study. The research finding indicated that the Covid-19 pandemic had a massive influence on the economy of the majority of SMEs operators, especially on their income generations which average losses in revenue of more than 50 percent during the Covid-19 pandemic compared to 2019. This resulted from the shutdown of their business activities to curb the spread of the Covid-19 pandemic. Other findings highlighted that the government’s initiatives to address the economic impact of SMEs yet insufficient to sustain business activities and income generations for instance access to financing facilities, product marketing opportunities and others. Therefore, required immediate initiatives should be made by all the stakeholders to reduce the economic impacts among the SMEs.
Disabled-Friendly Public Spaces in Covid 19 Pandemic: Improving Service Facilities and Accessibility based on the User‘s Perception in Alun-Alun Batu City
Authors: Purnamasari Wulan Dwi , Hanun Izdihar Farah , Sasongko Wisnu , Parlindungan Johannes
Published: September 2022

An inclusive and easily accessible public space, including for persons with disabilities, is one of the goals contained in the SDGs by 2030. The Batu City Government has tried to create a friendly public space by providing facilities and utilities that make it easier for people with disabilities to access it seen on Alun-Alun Batu. The ongoing covid 19 pandemic causes limited visits to Alun-Alun Batu and affects the condition of existing facilities. This research aims to develop the concept of facilities and accessibility based on the perception of disabled users. The analytical methods in this research are the perception assessment of disabled users with IPA analysis and the conformity assessment method according to the current pandemic conditions. The results show that out of 16 facilities, half of the facilities are in unsuitable condition and other facilities are not suitable for disabled users. The priority of upgrading facilities are objects in quadrants I IPA which consists of toilets, traffic parks, carousel, and gazebos/smoking areas. The second priority is facilities located in quadrant II such as parking lots, playgrounds, Ferris wheels, and offices. And the third priority is for facilities located in quadrant III IPA such as dancing fountains, stage performances, seats, rubbish bin, and tourism information.
The role of printed electronics and related technologies in the development of smart connected products
Authors: Buga C S , Viana J C
Published: September 2022

The emergence of novel materials with flexible and stretchable characteristics, and the use of new processing technologies, have allowed for the development of new connected devices and applications. Using printed electronics, traditional electronic elements are being combined with flexible components and allowing for the development of new smart connected products. As a result, devices that are capable of sensing, actuating, and communicating remotely while being low-cost, lightweight, conformable, and easily customizable are already being developed. Combined with the expansion of the Internet of Things, artificial intelligence, and encryption algorithms, the overall attractiveness of these technologies has prompted new applications to appear in almost every sector. The exponential technological development is currently allowing for the ‘smartification’ of cities, manufacturing, healthcare, agriculture, logistics, among others. In this review article, the steps towards this transition are approached, starting from the conceptualization of smart connected products and their main markets. The manufacturing technologies are then presented, with focus on printing-based ones, compatible with organic materials. Finally, each one of the printable components is presented and some applications are discussed.
Multi-round QAOA and advanced mixers on a trapped-ion quantum computer
Authors: Zhu Yingyue , Zhang Zewen , Sundar Bhuvanesh , Green Alaina M , Huerta Alderete C , Nguyen Nhung H , Hazzard Kaden R A , Linke Norbert M
Published: September 2022

Combinatorial optimization problems on graphs have broad applications in science and engineering. The quantum approximate optimization algorithm (QAOA) is a method to solve these problems on a quantum computer by applying multiple rounds of variational circuits. However, there exist several challenges limiting the application of QAOA to real-world problems. In this paper, we demonstrate on a trapped-ion quantum computer that QAOA results improve with the number of rounds for multiple problems on several arbitrary graphs. We also demonstrate an advanced mixing Hamiltonian that allows sampling of all optimal solutions with predetermined weights. Our results are a step toward applying quantum algorithms to real-world problems.
Analog quantum approximate optimization algorithm
Authors: Barraza Nancy , Alvarado Barrios Gabriel , Peng Jie , Lamata Lucas , Solano Enrique , Albarrán-Arriagada Francisco
Published: September 2022

We present an analog version of the quantum approximate optimization algorithm suitable for current quantum annealers. The central idea of this algorithm is to optimize the schedule function, which defines the adiabatic evolution. It is achieved by choosing a suitable parametrization of the schedule function based on interpolation methods for a fixed time, with the potential to generate any function. This algorithm provides an approximate result of optimization problems that may be developed during the coherence time of current quantum annealers on their way toward quantum advantage.
High-resolution real-space evaluation of the self-energy operator of disordered lattices: Gade singularity, spin–orbit effects and p-wave superconductivity
Authors: João S M , Viana Parente Lopes J M , Ferreira Aires
Published: September 2022

Disorder is a key factor influencing the behavior of condensed states of matter, however the true extent of its impact is generally difficult to determine due to the prominent roles played by quantum interference, entanglement between spin and orbital degrees of freedom and proximity to quantum critical points. Here we show that the one-particle disorder self-energy—a direct probe of the renormalization of low-energy excitations due to defects and impurities distributed randomly in a crystal—can be obtained by means of unbiased spectral expansions of lattice Green’s functions in a computationally expedient manner. Our scheme provides a powerful framework to map out the frequency and wavevector dependence of electronic excitations in unprecedented large tight-binding systems, up to 109 orbitals, with energy resolution only limited by the mean level spacing. We demonstrate the versatility of our approach in three distinct problems: (i) the Gade singularity in honeycomb layers with dilute topological defects; (ii) the rich landscape of impurity resonances in a spin–orbit-coupled ferromagnet; and (iii) the tailoring of emergent s-wave and p-wave superconducting phases in graphene via atomic defects. These examples reveal rich features in the disorder self-energy

Σ

dis

(

k

,
ω
)

that are absent from the self-consistent T-matrix approach and other common approximation schemes, which include regimes of nontrivial wavevector dependence and anomalous dependence upon the impurity concentration. Our study unravels puzzling, and so far largely inaccessible, manifestations of strong nonperturbative quantum interference effects in quantum materials and disordered phases of matter.
Physics-AI symbiosis
Authors: Jalali Bahram , Zhou Yiming , Kadambi Achuta , Roychowdhury Vwani
Published: September 2022

The phenomenal success of physics in explaining nature and engineering machines is predicated on low dimensional deterministic models that accurately describe a wide range of natural phenomena. Physics provides computational rules that govern physical systems and the interactions of the constituents therein. Led by deep neural networks, artificial intelligence (AI) has introduced an alternate data-driven computational framework, with astonishing performance in domains that do not lend themselves to deterministic models such as image classification and speech recognition. These gains, however, come at the expense of predictions that are inconsistent with the physical world as well as computational complexity, with the latter placing AI on a collision course with the expected end of the semiconductor scaling known as Moore’s Law. This paper argues how an emerging symbiosis of physics and AI can overcome such formidable challenges, thereby not only extending AI’s spectacular rise but also transforming the direction of engineering and physical science.
Convergence of the boundary integral method for interfacial Stokes flow
Authors: Ambrose David , Siegel Michael , Zhang Keyang
Published: September 2022

Boundary integral numerical methods are among the most accurate methods for interfacial Stokes flow, and are widely applied. They have the advantage that only the boundary of the domain must be discretized, which reduces the number of discretization points and allows the treatment of complicated interfaces. Despite their popularity, there is no analysis of the convergence of these methods for interfacial Stokes flow. In practice, the stability of discretizations of the boundary integral formulation can depend sensitively on details of the discretization and on the application of numerical filters. We present a convergence analysis of the boundary integral method for Stokes flow, focusing on a rather general method for computing the evolution of an elastic capsule or viscous drop in 2D strain and shear flows. The analysis clarifies the role of numerical filters in practical computations.
Computation of generalized matrix functions with rational Krylov methods
Authors: Casulli Angelo , Simunec Igor
Published: September 2022

We present a class of algorithms based on rational Krylov methods to compute the action of a generalized matrix function on a vector. These algorithms incorporate existing methods based on the Golub-Kahan bidiagonalization as a special case. By exploiting the quasiseparable structure of the projected matrices, we show that the basis vectors can be updated using a short recurrence, which can be seen as a generalization to the rational case of the Golub-Kahan bidiagonalization. We also prove error bounds that relate the error of these methods to uniform rational approximation. The effectiveness of the algorithms and the accuracy of the bounds is illustrated with numerical experiments.
Super-polynomial accuracy of one dimensional randomized nets using the median of means
Authors: Pan Zexin , Owen Art
Published: September 2022

Letffbe analytic on[0,1][0,1]with|f(k)(1/2)|⩽Aαkk!|f^{(k)}(1/2)|\leqslant A\alpha ^kk!for some constantsAAandα>2\alpha >2and allk⩾1k\geqslant 1. We show that the median estimate ofμ=∫01f(x)dx\mu =\int _0^1f(x)\,\mathrm {d} xunder random linear scrambling withn=2mn=2^mpoints converges at the rateO(n−clog⁡(n))O(n^{-c\log (n)})for anyc>3log⁡(2)/π2≈0.21c> 3\log (2)/\pi ^2\approx 0.21. We also get a super-polynomial convergence rate for the sample median of2k−12k-1random linearly scrambled estimates, whenk/mk/mis bounded away from zero. Whenffhas app’th derivative that satisfies aλ\lambda-Hölder condition then the median of means has errorO(n−(p+λ)+ϵ)O( n^{-(p+\lambda )+\epsilon })for anyϵ>0\epsilon >0, ifk→∞k\to \inftyasm→∞m\to \infty. The proof techniques use methods from analytic combinatorics that have not previously been applied to quasi-Monte Carlo methods, most notably an asymptotic expression from Hardy and Ramanujan on the number of partitions of a natural number.
The generalised Hausdorff measure of sets of Dirichlet non-improvable numbers
Authors: Bos Philip , Hussain Mumtaz , Simmons David
Published: September 2022

Let

ψ
:

R

+

→

R

+

\psi :\mathbb {R}_+\to \mathbb {R}_+

be a non-increasing function. A real number

x
x

is said to be

ψ
\psi

-Dirichlet improvable if the system

|

q
x
−
p

|

>
ψ
(
t
)
 
 

and

 
 

|

q

|

>
t

\begin{equation*} |qx-p|> \psi (t) \ \ {\text {and}} \ \ |q|>t \end{equation*}

has a non-trivial integer solution for all large enough

t
t

. Denote the collection of such points by

D
(
ψ
)

D(\psi )

. In this paper, we prove a zero-infinity law valid for all dimension functions under natural non-restrictive conditions. Some of the consequences are zero-infinity laws, for all essentially sublinear dimension functions proved by Hussain-Kleinbock-Wadleigh-Wang [Mathematika 64 (2018), pp. 502–518], for some non-essentially sublinear dimension functions, and for all dimension functions but with a growth condition on the approximating function.
The semidiscrete damped wave equation with a fractional Laplacian
Authors: Lizama Carlos , Murillo-Arcila Marina
Published: September 2022

In this paper we completely solve the open problem of finding the fundamental solution of the semidiscrete fractional-spatial damped wave equation. We combine operator theory and Laplace transform methods with properties of Bessel functions to show an explicit representation of the solution when initial conditions are given. Our findings extend known results from the literature and also provide new insights into the qualitative behavior of the solutions for the studied model. As an example, we show the existence of almost periodic solutions as well as their profile in the homogeneous case.
On Russell typicality in set theory
Authors: Kanovei Vladimir , Lyubetsky Vassily
Published: September 2022

According to Tzouvaras, a set is nontypical in the Russell sense if it belongs to a countable ordinal definable set. The class

H
N
T

\mathbf {HNT}

of all hereditarily nontypical sets satisfies all axioms of

Z
F

\mathbf {ZF}

and the double inclusion

H
O
D

⊆

H
N
T

⊆

V

\mathbf {HOD}\subseteq \mathbf {HNT}\subseteq \mathbf {V}

holds. Several questions about the nature of such sets, recently proposed by Tzouvaras, are solved in this paper. In particular, a model of

Z
F
C

\mathbf {ZFC}

is presented in which

H
O
D

⫋

H
N
T

⫋

V

\mathbf {HOD}\subsetneqq \mathbf {HNT}\subsetneqq \mathbf {V}

, and another model of

Z
F
C

\mathbf {ZFC}

in which

H
N
T

\mathbf {HNT}

does not satisfy the axiom of choice.
Linearly continuous maps discontinuous on the graphs of twice differentiable functions
Authors: Ciesielski Krzysztof , Rodríguez-Vidanes Daniel
Published: September 2022

A function

g
:

R

n

→

R

g\colon \mathbb {R}^n\to \mathbb {R}

is linearly continuous provided its restriction

g
↾
ℓ

g\restriction \ell

to every straight line

ℓ
⊂

R

n

\ell \subset \mathbb {R}^n

is continuous. It is known that the set

D
(
g
)

D(g)

of points of discontinuity of any linearly continuous

g
:

R

n

→

R

g\colon \mathbb {R}^n\to \mathbb {R}

is a countable union of isometric copies of (the graphs of)

f
↾
P

f\restriction P

, where

f
:

R

n
−
1

→

R

f\colon \mathbb {R}^{n-1}\to \mathbb {R}

is Lipschitz and

P
⊂

R

n
−
1

P\subset \mathbb {R}^{n-1}

is compact nowhere dense. On the other hand, for every twice continuously differentiable function

f
:

R

→

R

f\colon \mathbb {R}\to \mathbb {R}

and every nowhere dense perfect

P
⊂

R

P\subset \mathbb {R}

there is a linearly continuous

g
:

R

2

→

R

g\colon \mathbb {R}^2\to \mathbb {R}

with

D
(
g
)
=
f
↾
P

D(g)=f\restriction P

. The goal of this paper is to show that this last statement fails, if we do not assume that

f
f

is continuous. More specifically, we show that this failure occurs for every continuously differentiable function

f
:

R

→

R

f\colon \mathbb {R}\to \mathbb {R}

with nowhere monotone derivative, which includes twice differentiable functions

f
f

with such property. This generalizes a recent result of professor Luděk Zajíček [On sets of discontinuities of functions continuous on all lines, arxiv.org/abs/2201.00772v1, 2022] and fully solves a problem from a 2013 paper of the first author and Timothy Glatzer [Real Anal. Exchange 38 (2012/13), pp. 377–389].
A pointed Prym–Petri Theorem
Authors: Tarasca Nicola
Published: September 2022

We construct pointed Prym–Brill–Noether varieties parametrizing line bundles assigned to an irreducible étale double covering of a curve with a prescribed minimal vanishing at a fixed point. We realize them as degeneracy loci in type D and deduce their classes in case of expected dimension. Thus, we determine a pointed Prym–Petri map and prove a pointed version of the Prym–Petri theorem implying that the expected dimension holds in the general case. These results build on work of Welters [Ann. Sci. Ëcole Norm. Sup. (4) 18 (1985), pp. 671–683] and De Concini–Pragacz [Math. Ann. 302 (1995), pp. 687–697] on the unpointed case. Finally, we show that Prym varieties are Prym–Tyurin varieties for Prym–Brill–Noether curves of exponent enumerating standard shifted tableaux times a factor of22, extending to the Prym setting work of Ortega [Math. Ann. 356 (2013), pp. 809–817].
Fusion systems with 2-small components
Authors: Aschbacher Michael
Published: September 2022

We show that there are no odd simple 2-fusion systems

F

\mathcal {F}

in which the centralizer of some fully centralized involution contains a component

C

\mathcal {C}

that is the 2-fusion system of a simple group

K
K

such that

C

\mathcal {C}

is J-maximal or maximal and subintrinsic in

C

(

F

)

\mathfrak {C}(\mathcal {F})

, as appropriate, and such that

K
K

is of Lie type over the field of order 2, but not

S

p
n

(
2
)

Sp_n(2)

or

F
4

(
2
)

F_4(2)

; or

K
K

is one of many sporadic groups; or

K
K

is

P

Ω
8
+

(
3
)

P\Omega _8^+(3)

.
Entropy formula for systems with inducing schemes
Authors: Alves José , Mesquita David
Published: September 2022

We obtain entropy formulas for Sinai–Ruelle–Bowen (SRB) measures with finite entropy given by inducing schemes. In the first part of the work, we obtain Pesin entropy formula for the class of noninvertible systems whose SRB measures are given by Gibbs-Markov induced maps. In the second part, we obtain Pesin entropy formula for invertible maps whose SRB measures are given by Young sets, taking into account a classical compression technique along the stable direction that allows a reduction of the return map associated with a Young set to a Gibbs-Markov map. In both cases, we give applications of our main results to several classes of dynamical systems with singular sets, where the classical results by Ruelle and Pesin cannot be applied. We also present examples of systems with SRB measures given by inducing schemes for which Ruelle inequality does not hold.