bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stability of beta-induced Alfvén eigenmodes (BAE) in DIII-D
Authors: Heidbrink W.W. , Van Zeeland M.A. , Austin M.E. , Crocker N.A. , Du X.D. , McKee G.R. , Spong D.A. 
Published: April 2021

Abstract
Although the stability of ellipticity, toroidal and reversed-shear Alfvén eigenmodes (EAE, TAE, RSAE) are relatively well understood, less is known about the stability of lower-frequency modes such as the beta-induced Alfvén eigenmode (BAE) but, because they are often unstable in present devices and are implicated in fast-ion transport, understanding their stability is vital. BAE stability is studied in primarily weak or reversed shear DIII-D plasmas with sub-Alfvénic deuterium beams. Modes are classified based on electron cyclotron emission, beam emission spectroscopy, magnetics, and interferometer data. The study is limited to the initial two seconds of the discharge, where the evolving q profile provides an effective scan of the dependence of stability upon q. In a dedicated experiment, BAEs are unstable at times in the discharge when the minimum of the safety factor q
min is close to a rational number. The observed mode frequencies are usually close to analytic estimates of the BAE accumulation point and the eigenfunction peaks in the vicinity of q
min. Unstable BAEs usually occur in bursts that chirp rapidly in frequency. To isolate the importance of thermal and beam gradients in driving the modes, the beam and electron cyclotron heating power is altered for 50–100 ms durations in reproducible discharges. As expected from the resonance condition, BAEs depend sensitively on the beam power and injection geometry. Modes only persist for ∼25 ms because the anisotropic beam population only interacts strongly with the modes over a relatively narrow range of q. A database of over 1000 beam-heated discharges shows that BAEs are more likely to be unstable when the poloidal beta exceeds 0.5.
Application of the elliptic approximation model for the edge turbulence rotation measurement via the poloidal correlation reflectometer in Wendelstein 7-X
Authors: Han X. , Krämer-Flecken A. , Xiang H.M. , Vécsei M. , Knieps A. , Windisch T. , Anda G. , Andreeva T. , Bozhenkov S.A. , Geiger J. , Dunai D. , Trier E. , Rahbarnia K. , Zoletnik S. , Liang Y. , W7-X Team the 
Published: April 2021

Abstract
The perpendicular velocity (v
⊥) of turbulence is measured by means of a hopping poloidal correlation reflectometer diagnostic for the study of turbulence rotation in the plasma edge region in Wendelstein 7-X. An elliptic approximation (EA) model is applied for calculating the space-time correlation in the edge region. The v
⊥ profile is compared in the high-ι (edge ι ≈ 1.2) and limiter (edge ι < 1) configurations. It is found that the v
⊥ gradient is inversely proportional to the heating power in the high-ι configuration, which could be attributed to the turbulence activities in the plasma edge. In the limiter configuration, the v
⊥ spike is observed near the island boundary, which is corresponded to the plasma current crash. In the standard configuration (edge ι ≈ 1), the v
⊥ profile in the island region distributes as a function of the perpendicular separation. With increasing of the plasma current, the island enlarges the size as is referred from the v
⊥ scope, accompanying with steepening of the v
⊥ gradient at the boundary of the island.
Retraction: Research on Multimodal Emotion Analysis Algorithm Based on Deep Learning (J. Phys.: Conf. Ser.
1802 032054)
Authors: Xiao Xuan , Yang Jie , Ning Xinyi 
Published: April 2021

IOP Publishing Limited ("IOPP") is retracting this paper following an investigation in accordance with COPE guidelines. which has confirmed translated plagiarism.

This work was originally published in Chinese [1] and has been translated and published without permission or acknowledgement to the original authors. IOP Publishing Limited request any citations to this article be redirected to the original work [1].

IOPP have made multiple attempts to contact the author but has not received a response. The author is encouraged to contact jpconf@ioppublishing.org.

[1] LIN Min-hong, MENG Zu-qiang. Multimodal Sentiment Analysis Based on Attention Neural Network[J].Computer Science, 2020, 47(11A): 508-514.
Retraction published: 23 April 2021
The implications of technological progress in architectural thinking: The future impossibility for an architecture of hiding
Authors: Beqiri J 
Published: April 2021

Abstract
This paper aims at exploring the future of architecture of hiding which is encountering the constant pressure of technological advance. The open society and its increasing surveillance are requiring human behaviour to adjust to new realities of hiding. One estimate puts the number of surveillance cameras around the world at 245 million and another reckons there will soon be over twice that number in China alone [1]. Consequently, the perception of hiding architecture is changing, and its romanticism is facing a serious threat. Up to 20th century, hiding an object - space - to the degree of resembling alienation or nothingness assumed meanings addressed to intellect and to the body, meanings imposed by threats or by sanctions. In its ancient Greek version, one could grasp the space by means of a thought-process capable of perceiving them as a totality and endowed with meaning. But today, the boundaries between inside and outside are being dissolved for an observer who through technological means is able to move freely in space and time, defeating the hiding architectures and its three-dimensional spatial perception. To quote Henri Michaux: “I put an apple on my table. Then I put myself inside this apple. What peace! [2]” The advance of technology has made hiding a matter of self-perceiving which has only a distant link to geographical reality. The underground space remains the prime solution for hiding but the increasing conversion of underground structures and military fortifications into data centres tells that the importance of data storing is surpassing that of physical hiding. Instead, the architecture of hiding is transforming into the architecture of living without traces. Technological progress is taking us to a milieu in which the tracelessness of the fugitive becomes the representation of the hidden space. However, as Peter Sloterdijk puts it forward in Bubbles [3], what lends modern psychological knowledge its strength and autonomy is that it has shifted the human position beyond the reach of geometry. Now, the space created is being conceived before it is actually “lived”, meanings are no longer conveyed by a continual putting-to-the-test of the emotions, and humankind is adjusting to new realities by finding other means of hiding, presumably through architecture of data and digital cryptography.
Willingness to walk in underground space – evidence from Singapore
Authors: Zacharias J , Wang B 
Published: April 2021

Abstract
Research on the environmental factors in promoting longer walks has focussed on the outside environment. This research concerns factors in the willingness to walk (WTW) in underground space, in a tropical climate, that of Singapore. Participants were accompanied on a pre-determined itinerary and responded to a questionnaire at intervals on perceptions of their experience and their willingness to continue walking. Several environmental factors were related to WTW. Participants ranked corridor width and the volume of pedestrians as the most important factors in comfort. Although WTW observed a distance-decay function as expected, there were restoration episodes across the participant group, strongly suggesting conditions that enable longer walks in underground space.
Principles of the integrated development of Moscow City underground space
Authors: Konykhov D.S. , Kolybin I.V. 
Published: April 2021

Abstract
Moscow is the most dynamically developing metropolis in the Russian Federation. This is a city with almost a thousand-year history, where about 12.65 million people live on an area of 2.5 thousand km2. The economic efficiency of the underground space utilization is characterized by the ratio of the area of the underground part of the structure to its total area. Said ratio on average is less than 8% for the city of Moscow. From 2011 to 2019, 50 new metro stations and about 82 km of new metro lines were built in Moscow. By the end of 2027, it is planned to build 329 km of new lines and 151 stations. The housing renovation program provides for the renovation of 5175 residential buildings with maximum utilization of the underground space to ensure a comfortable living for people. The report considers the basic principles, goals and objectives of the integrated development of the underground space of Moscow, indicated in the Code “High rise buildings and complexes. Regulation of urban planning”. A review of accumulated experience in the construction and operation of residential areas of Moscow, built on the autonomous principle of “city in city”. Methods for ensuring the integrity and technological safety of existing buildings with integrated development of the underground space are considered.
Research on the development and utilization of underground space in Beijing Old City
Authors: Shi Xiaodong , Zhao Yiting , Wu Kejie 
Published: April 2021

Abstract
As a concentrated embodiment of urban historical sites, cultural relics and cultural heritage, the old city of Beijing has the most intensive historical and cultural resources and the most stringent requirements for historical protection. At the same time, it also faces a series of development problems to be solved, such as insufficient development space, lagging public service facilities, and urgent improvement of living environment. How to effectively utilize the underground space resources and coordinate the relationship between historical protection and urban renewal is an important issue for the sustainable development of the old city of Beijing. In this paper, the development and utilization strategies of the underground space in the old city of Beijing are systematically studied, as well as the reasonable utilization methods of the underground space in the historical protection areas. Through the development and utilization of underground space, we can make up for the shortage of public service and better improve the ground space environment. In addition, this paper also discusses the integrated development of underground space and metro stations, so as to enhance the urban renewal and development of the station areas. The relevant data and conclusions are from the latest planning and practical experience of Beijing old city, in order to provide useful reference for the sustainable development of historical urban areas and the scientific utilization of underground space resources.
Underground space in metro area: constituent, influencing factors and improving strategies of the spatial vitality
Authors: Xu YJ , Bai X , Chu KF 
Published: April 2021

Abstract
Nowadays, the shortage of available urban land and the booming construction of urban subway are driving the rapid development of Underground Space in the Metro Area (USIMA) which is an important constituent in the compact development of cities. Spatial vitality, as one of the most important evaluation indicators for the layout of such metro-related underground space, is closely related to spatial efficiency. Therefore, taking Shanghai People’s Square Metro Station (SPSMS) as a case study, this paper investigated the variable factors of the spatial vitality in USIMA by using methods of space syntax, field investigation, and pedestrian counting. Results revealed that the spatial vitality of USIMA is comprehensively affected by related variables, including accessibility and visibility of spatial configuration, degree of functional mixture, layout of station hall as well as entrances/exits, and the organization of business forms. Finally, improvement suggestions and discussions are put forward from the aspects of entrance/exit layout, spatial organization, and functional distribution, to provide reference for future planning, design and optimization of USIMA with effective vitality.
A perspective on the governance of London’s subsurface
Authors: Von Der Tann L , Metje N , Collins B , Melo Zurita M 
Published: April 2021

Abstract
The role of the urban subsurface for cities has long been disregarded but is recently getting more attention. To capture it, the city’s geographical and geological setup, its history and the social context it is located within are of particular relevance. As a case study, this paper illustrates the context and governance of London’s subsurface through the lens of a ‘governance arrangement’ looking at these three elements. It is highlighted that feedback loops between the material reality and the societal context – human influences on the subsurface environment – are not sufficiently recognised. The paper demonstrates how the discretionary nature of the UK’s planning system puts local planning authorities on the one hand, and engineers and technical knowledge on the other hand, in central positions to mediate strategic plans and influence specific project applications and decisions. From the empirical analysis presented here, no sense of urgency is assigned to the concept of underground space planning in London at this moment in time. However, the analysis suggests a need for better understanding of the spatial and material effects of specific interventions, as well as of the according policies and strategies. Current discourses around underground data sharing or geothermal energy provision could facilitate the process towards a spatial integration of the various strategies that are in place.
The network pattern of underground pedestrian system and its role to urban resilience
Authors: Zhao Ziwei , Xie Jinrong , Zhang Chenhao , Guo Dongjun , Chen Yulu , Yuan Yuan 
Published: April 2021

AbstractIn recent years, underground pedestrian system (UPS) has been developed worldwide, especially within central megacity areas, but research on UPS characteristics is still in the qualitative description stage, and quantitative methods are lacking to assess the impact of UPS on resilience. Therefore, it is essential to quantitatively measure UPS resilience and thus be able to make decisions on how UPS can be improved. The authors propose topological analysis of UPS networks based on computational and functional graph representations, which represents a new approach to theoretical discussions and empirical evidence for planning and configuring a UPS, thereby contributing to urban resilience. These representations provide functional views in which nodes represent single underground spaces and links represent underground sideways. Various graph measures are computed for structural analysis, and results provide insights into the required physical properties for planning resilient UPS. Based on validations applied to two typical high-density areas in Nanjing Xinjiekou and Guangzhou Zhujiang New Town, China, the authors examine how different UPS network patterns influence resilience performance, then further discuss the social and economic factors affecting network patterns, and give suggestions.
Waterproofing for buried decks
Authors: Hickman BSD 
Published: April 2021

AbstractBuried decks are an increasingly common feature in the modern built environment. This increase may be partly attributed to growing awareness of the need for sustainability. Green roofs, sustainable urban drainage, water attenuation and even parks and farms are being located on top of ground floor roof structures and cut and cover tunnels. Waterproofing of these decks is vital in order to use the space created beneath and, also, to prolong the life expectancy of the structure.This research explores some of the available best practice guidance and then compares the key waterproofing design features with opinions from industry. Opinions are gathered through seventy-eight questionnaire respondents made up of UK based professionals dealing with waterproofing of buried decks.This research suggests that buried deck waterproofing design can reduce risk by employing the following features: (a) reinforced concrete structural deck, (b) fully-bonded waterproofing membrane, (c) waterproofing laid to a gradient to falls, and (d) provision of a drainage void over the waterproofing layer.As a result of these findings this paper calls for more authoritative best practice guidance on buried deck waterproofing design in a bid to reduce pressures in procurement that lead to weaker waterproofing design choices.This research may be of interest to those involved in the design and construction of underground structures including cut and cover tunnels, station boxes, malls, basements and more. The research identifies some fundamental features of podium deck waterproofing design and clarifies which design choices are perceived to deliver more robust waterproofing than others.
Subsea tunnel linking Föglö with the main island in Åland
Authors: Grøv E , Høyar O , Holmstrøm H M 
Published: April 2021

Abstract
The paper describes a well considered subsea road tunnel in Åland, Finland which will hopefully start in the very near future. The paper describes partly the socio-economics and public benefits of such a project in Åland and partly some technical aspects of designing and constructing road tunnels under the sea to connect land masses. The tunnel is expected to be constructed along the lines of similar rock tunnels being constructed and entered into successful operation in many of the Scandinavian/Nordic countries. More important though is the vital role such a project will serve for the society in Åland. The project is not one that serves millions of people in busy mega cities – still it is a pleasure to see a mega project for a small community mature, starting from a sketchy plan made by individual enthusiasts to a solid plan for a multi-million Euro investment.
St1 Deep Heat Project: Geothermal energy to the district heating network in Espoo
Authors: Kukkonen I T , Pentti M 
Published: April 2021

Abstract
St1 Deep Heat Project with its two deep wells extending to 6.2 - 6.4 km depth is the world’s deepest industrial geothermal energy project. The aim is to build an EGS (enhanced geothermal system) at the depth of about 5 - 6 km. The project is a pilot aiming at exploring the technical and economic feasibility of geothermal energy in the crystalline rock conditions of Finland for production of thermal power to a district heating network. Due to the demands of the district heating, the aim is to produce hot fluid at about 100°C and re-inject it to the formation at 50°C. The 100°C goal requires to drill to about 6 km depth. The drill site is located in Espoo, next to the Fortum district heating plant on the Aalto University campus. So far (2020) the project has drilled a 2 km deep completely cored pilot hole (OTN-1), and two deep wells OTN-2 to 6.2 km and OTN-3 to 6.4 km. Hydraulic conductivity has been enhanced by hydraulic stimulation in both deep wells in 2018 and 2020. The extreme depth level sets significant challenges for drilling and hydraulic stimulation, as well as controlling of induced seismicity. At present, the project proceeds with the installation of production pumps in OTN-2 and OTN-3, and first test cross-hole pumpings are expected to start in January 2021. In the presentation we provide an insight to the project and its major achievements and challenges.
An edge-computing-based sensing system for geo-structure risks
Authors: Huang Ruida , Fan Yiqun , Liu Yi 
Published: April 2021

Abstract
With the advancement of geo-structures (including tunnels and underground space projects), risk management strategy has been developing rapidly in China since the 1990s. Its current practice, however, mainly focuses on the assessment of structures with qualitative or quantitative method. Currently, less attention is paid to risk control, which results in the lagged response to risk events. In this paper, risk management strategy of geo-structures at operation stage is discussed. Furthermore, an edge-computing-based risk sensing system, mainly based on image recognition, consisting of a set of cameras, edge gateways and wireless network, is proposed. The system offers real-time monitoring for structural and operational performance, and edge computing to sense early risks within geo-structures. A preliminary test of the system has been conducted.
Enhancing underground development users’ health through facilities management: a study of the underground metro system in Hong Kong
Authors: Chan Isabelle , Soh Chee Kiong , Chen Hao 
Published: April 2021

Abstract
The ever-rising global population poses a great challenge for cities to accommodate additional citizens in limited land space. As such, many high-density cities were transforming the mind from “build higher” to “dip deeper”. However, most of the existing underground space were built with inadequate consideration of user’s health. Thus, this study aims to enhance underground users’ health using an integrated Facilities Management-Health (FM-H) model. A questionnaire survey study was conducted in 4 underground metro stations in Hong Kong, which resulted in 120 valid survey responses. Based on the extensive literature review, the survey was designed to cover eight FM factors: thermal comfort, indoor air quality, ventilation, visual comfort, noise level, greenery, wayfinding support, and immediate access, and four health indicators: physical health, emotional exhaustion, depersonalization and claustrophobia stress. Pearson’s correlation and multiple regression modelling were adopted to investigate the associations between FM and users’ health. The results indicate that, even though all FM factors were found to have a significant impact to at least one health indicator, thermal comfort and wayfinding support were found to have impacted on three health indicators respectively. This sheds light to the importance of needing further investigation into these two FM factors in underground studies.
Fire safety issues in underground spaces: a need for regulatory evolution – French, Swiss and Hong Kong SAR, China (Hong Kong) contexts
Authors: Moreau B , Deffayet M , Chan I , Lam F , Chau P , Bettelini M , Ng F , Au G 
Published: April 2021

Abstract
Current regulations and operational safety requirements impose onerous constraints that make it difficult to be fulfilled by practical design of underground projects acceptable to all stakeholders. The ACUUS working group on fire safety of underground spaces intends to gather and share information on the ways how fire safety is taken into account and managed in different countries. This article presents the first work carried out within this working group. Regulatory contexts in France, Switzerland and Hong Kong SAR, China (Hong Kong) are presented, highlighting the current limitations. With their similarities and differences, the French, Swiss and Hong Kong contexts reveal a need to improve and to develop their respective regulations to allow pragmatic solutions without compromising fire safety. Underlying principles that condition fire safety requirements are defined in order to develop new approaches to overcome the aforementioned limits.