bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the issue of improving the accuracy of construction cost calculations at the pre-project stage
Authors: Dobysheva T V 
Published: May 2021

Abstract
The article deals with the issues of determining the cost of construction products on the territory of the RF at the pre-project stage. The results of the obtained calculations of the construction cost at the pre-project stage are analyzed using various methods. The disadvantages of determining the cost of construction using the enlarged collections of the CPS-2020 are revealed. Ways to improve the accuracy of construction cost calculations at the pre-project stage are proposed, in particular, by applying extrapolation formulas that are currently not available in the methodology for calculating construction costs based on enlarged collections. It is proved that the application of the proposed formulas significantly increases the accuracy of calculations, bringing the obtained values closer to the most accurate calculation of the construction cost – the result of the consolidated estimated calculation of the construction cost, compiled within the project documentation.
The strategy of regional development: cluster formation methods
Authors: Dorzhieva E L , Kirillova T K 
Published: May 2021

AbstractThe article discusses the cluster approach to the regional economic development. It describes the method of creating a spatially localized recreational cluster. The method for calculating the integral indicator of clustering has been improved. The indicators of recreational development have been added to the group of regional economic development indicators. To assess the correctness of the results, the integral indicator for assessing the regional socio-economic development has been calculated by the multifactor ranking method. It involves the calculation of the Euclidean metric, which shows the deviation of the integral indicator from the standard. The main risks of spatially localized recreational clusters have been identified.
Rolling verification of the performance of real estate investment funds
Authors: Gercekovich D A , Yu Gorbachevskaya E 
Published: May 2021

Abstract
Currently, there is an urgent need to develop an institutional rental housing market. It is an obvious fact that this issue cannot be resolved without the formation of available investment resources. This article discusses aspects of one of these promising forms – real estate investment funds. The article uses historical data on the dynamics of profitability of the 21st real estate fund for 2013 -2020 to test the method of assessing the risks of investing funds for potential investors – the method of sliding verification of groups of leaders synthesized using the “Yield-risk” model. The model is based on the basic principles of portfolio analysis. The results obtained indicate the suitability of the proposed method. Testing was carried out on current data from 2017-2020, which were not used to build the model. The constructed groups of leading funds demonstrate their continuity at all stages of rolling verification. The conducted correlation analysis showed a fairly close mutual correlation between the dynamics of profitability of the studied real estate funds, which significantly weakens by 2020. The proposed method can be used when making decisions about investing money in investment real estate, including rental housing of various categories.
Institutional rental housing market – new approaches and formats
Authors: Yu Gorbachevskaya E , Gimelshtein I V 
Published: May 2021

Abstract
Russia needs to create an institutional, civilized commercial rental market. its practical absence today limits the territorial mobility of the population and significantly reduces the flexibility of the labor market. To accelerate the mechanisms of economic development by attracting the best specialists and retaining their own human capital, it is possible that this will make commercial rental housing available in the largest cities with full legal protection of the tenant and owner from fraud. The development of the rental market is influenced by many factors: demand and preferences from potential consumers, availability of financial resources, technical and technological capabilities, population structure, etc. All this determines the requirements for new rental housing formats and makes it necessary to develop new investment mechanisms. The article discusses the current state of the rental housing segment in Russia. Most attention is paid to the developing formats of rental housing such as apartments, coliving and retirement homes. Their characteristics, classifications and prospects for the development of construction of such projects in Russia are presented. The rental segment of the residential real estate market creates new prospects for the spatial development of cities and regions, improving the situation related to personnel problems at large enterprises and increasing the mobility of the population.
Development of civil engineering financing forms and their influence on the development’s economy
Authors: Kogan A B 
Published: May 2021

Abstract
The purpose of this work is to study the influence of financing housing construction methods on the financial and economic characteristics of projects for apartment buildings construction (AB) and on price level of the primary Residential Real Estate Market. The methodological foundations of the research work are the rules for financing housing construction and other standards in this area, tax standards, rules for developing construction schedules, methods for assessing the investments effectiveness. Theoretical foundations of work are the work of leading scientists in the field of real estate development, provisions on the rules of pricing in the primary Real Estate Market, provisions of the finance and entrepreneurship theories. Information bases of work are market information on the primary Real Estate Market state (Novosibirsk) and the estimated cost of apartment buildings. The evolution of financing housing construction methods in the Russian Federation is described. Two modern methods are considered: financing with the use of agreements for participation in shared construction and financing, using real estate purchase and sale agreements (PSA). On the example of an apartment building, created in the city of Novosibirsk, calculations were made of the project implementation results for the AB construction, using both funding methods: (PAShC and PSA). The contradictions of the indicators describing these results are shown and explained (using PSA, the profit is higher; however, the internal rate is higher, using PAShC). The assessment of the initiative implementation consequences to ban PAShC is given.
Innovative technologies in the Russian construction industry as a factor of economic development
Authors: Timchuk O G , Kazantseva I I 
Published: May 2021

Abstract
The construction sector is a priority area of the economy, which affects the quality of life of the population. The dynamics of construction is one of the key indicators by which one can judge the economic and social development of the country. At the same time, in recent decades the investment and construction industry of Russia experiences a number of problems that hinder its development. First of all, they include a low proportion of qualified personnel; underdevelopment of the competitive environment due to a relatively low share of small and medium-sized enterprises in the structure of the construction industry; poor legal regulation of the construction sector; low investment efficiency; inconsistency of building codes and regulations with modern requirements for construction projects; the lack of a well-developed mechanism for coordinating inter-firm interactions. The article discusses the main factors influencing the innovative development of enterprises in the construction industry. The system of indicators characterizing the structural components of the innovative potential of the enterprise is presented. The authors have developed an organizational economic mechanism for implementing innovations in the construction sector.
Prediction of dissolved oxygen content in water based on EEMD-Pearson and LSTM hybrid models
Authors: Li Qihua , Wang Xin , Wang Jiangying , Zhou Yun 
Published: May 2021

Abstract
Improving the accuracy of dissolved oxygen (DO) prediction and establishing a water body DO prediction model are of great importance in water environment pollution management and planning management. In this paper, we propose a hybrid model (EEMD-Pearson-LSTM) of ensemble empirical modal decomposition-Pearson analysis and long-short memory neural network (LSTM), which firstly uses EEMD to decompose the non-stationary dissolved oxygen data into several sub-series that are easy to analyze, and secondly uses Pearson correlation analysis method to The screened subsequences are input to the LSTM network for training and prediction. By establishing the conventional LSTM model, EEMD-LSTM model, EEMD-BP model, and EEMD-Pearson-BP model for comparison under different time periods, root mean square error (RMSE), mean absolute error (MAE), mean absolute percentage error (MAPE), and coefficient of determination (R2) were used as evaluation indicators. In predicting the first 90 days of data, the RMSE, MAE, MAPE, and R2 of the EEMD-Pearson-LSTM model were 0.2355, 0.1893, 2.4710, and 0.8787, respectively, which were optimized by 37.88%, 35.44%, 37.42%, and 28.15%, respectively, compared with the traditional LSTM model, and the EEMD- LSTM model by 13.74%, 16.46%, 16.82%, and 4.98%, respectively, and the error of EEMD-BP network by 23.93%, 22.70%, and 24.32%, respectively, and its R2 by 11.17%, and the error of EEMD-Pearson-BP network by 18.62%, 14.07%, and 14.44%, and its R2 improved by 7.58%. To further demonstrate the advantages of EEMD-Pearson-LSTM, the prediction models for 30-day and 60-day time periods were selected for comparison, and the results showed that EEMD-Pearson-LSTM outperformed other models for the prediction of dissolved oxygen content in different time periods.
Effects of aging methods on properties of rubber powder modified asphalt
Authors: Kaikai Gao , Abulimiti Nuermaimaiti , Zhiqiang Huo , Zheng Xun Yang , Fang Chen 
Published: May 2021

Abstract
Three types of aging methods were conducted on rubber powder modified asphalt, and the basic physical properties test, dynamic shear rheological test and infrared spectrum analysis were adopted to study the effect of aging methods on properties of rubber powder modified asphalt comprehensively. Results show that effects of different aging methods on physical properties of rubber powder modified asphalt are inconsistent. There is a slight influence of aging on its rheological properties, which means a better aging resistance. Through microanalysis, it can be found that there is a significant aging for rubber powder modified asphalt after pressurized aging, followed by the ultraviolet aging. The aging degree of rubber powder modified asphalt is relatively small after short-term thermal-oxidative aging.
Migration and transformation of three nitrogen in groundwater and antipollution effect of aquitard in North China Plain typical area
Authors: Zhao Yanjie , Deng Yirong , Lu Haijian , Lv Mingchao , Cheng Zhou 
Published: May 2021

Abstract
The “three nitrogen” (NH4
+-N, NO2
—N, NO3
−-N) pollution of groundwater in north China plain region endanger the groundwater ecological environment. In this study, we chose the typical area of North China Plain as the representative research area. By numerical method, we analyzed the migration characteristics of “three nitrogen” pollutants in the 200 year time scale in different representative strata structural modes of shallow groundwater system in this area. Based on the simulation results, the retardant ability of the unit thickness of aquitard was analyzed. The results were as follows: 1 The migration of different kinds of “three nitrogen” pollutants in the aquifer system were different; (2) The strata structural characteristics have obvious effects on the migration of “three nitrogen”, and their influence rules were different. The three representative strata structure models were constructed on the basis of comprehensive analyzing the regional strata features. Therefore, the simulation results have reference value for evaluation of the “three nitrogen” migration and the retardant ability of the aquitard in this area.
Study on the properation and properties of PP/mental aluminium power composites
Authors: Dou Yanli , Huang Jiaming , Yao Weiguo , Li Jinliang , Guan Dongbo 
Published: May 2021

Abstract
In this paper, polypropylene(PP) was blended with aluminum powder, porous powder and EVOH reinforcing agent in different proportions by melt blending method. The infrared spectrum analysis of the blending components was carried out to study the tensile strength, impact strength, ball indentation hardness and heat resistance of the composites with different proportions. The results show that when the content of aluminum powder is 2 wt.%, the content of porous powder is 9 wt.%, and the content of EVOH is 4 wt.%, the heat resistance of the composite is the best. The tensile strength, impact strength and hardness of the composite are 21.33 MPa, 1.83 MPa and 74.78 N/mm 2, respectively. At this time, the composite has the best comprehensive properties.
Dynamic prediction model of bridge project life cycle cost investment based on decision tree algorithm
Authors: Li Jing , Li Xu , Zhang Zhuoqun 
Published: May 2021

Abstract
In order to further improve the dynamic prediction effect of bridge engineering life cycle cost, a life cycle cost prediction model of bridge engineering is established by using decision tree algorithm, and the influence coefficient of bridge engineering characteristics on cost is analyzed by data acquisition method. After analysis, the project characteristics which have great influence on the cost of bridge engineering are determined. The decision tree algorithm is used to establish the dynamic prediction model of bridge engineering life cycle cost; through MATLAB software, a good bridge cost prediction model is gradually established, and the model is trained, modified and verified according to the actual engineering data. The dynamic prediction model of life cycle cost investment of bridge engineering is established by using decision tree algorithm, which effectively improves the prediction accuracy and has strong practicability.
The Convertibility Forecast Model of Space Structure in Architecture Programming——Collective Housing in Taiwan for example
Authors: Shyng  , Jyh-Harng  
Published: May 2021

Abstract
House refurbishment related to the convertibility of space organizations is nowadays a common phenomenon in Taiwan, reflecting user demands for the diversity of unit plane and space expansion in quantity, and forming an important research topic over the implementation of sustainable development concept in living environment. In this paper, apartment mansion-type amalgamated dwellings were quantitatively analyzed and investigated, and four models, which were dimension combinations of influence factors, were compared through the field survey and logistic regression model (binary regression method). The results showed that the variables in Model IV consisted of three dimensions—space organization, building entity and spatial planning, with the optimal prediction rate (74.5%), so it was regarded as a convertibility prediction model of space organization; the significance and goodness of fit of each model were analyzed by comparing each variable coefficient with the expected symbol, and next, the concrete meaning of each influence factor belonging to each dimension of each model was indicated by means of coefficient correction, which could further predict the convertibility of space organizations, accurately obtain the factors influencing the convertibility prediction, and improve the prediction accuracy. This research, which conforms to the concept of sustainable environmental development, will contribute to construction project planning and design of residential buildings.
Finite Element Analysis of Pipe Shed Pre-Supporting Reinforcement Effect on A Shallow-Buried Tunnel
Authors: Su Jianping , Wang Tao 
Published: May 2021

Abstract
Under the engineering background of crushed zone at the entrance section of a shallow-buried soft rock tunnel, the 3D finite element simulation of pipe shed pre-reinforcement measures was implemented under different diameters, lengths, and spacing via Midas Civil software after the excavation of tunnel portal, in an effort to analyze the reinforcement principle of pipe shed grouting reinforcement method during the tunnel excavation process. The stress-induced deformation laws of the support system were summarized, and the reinforcement effect of pipe shed grouting method was analyzed. The results show that with the increase in diameter of pipe shed, the maximum deformation of pipe shed is obviously reduced, and the favorable effect is reached when the diameter of pipe shed is within 300-600 mm. As the pipe shed extends to the undisturbed zone of soil mass, the change in length has a very minor effect on the deformation of pipe shed, while the deformation is greatly impacted by the excavation footage, and the deformation becomes the most significant after the excavation footage becomes greater than 1.5 m.
Large eddy simulation of the variable density mixing layer
Authors: Huang J X , Hug S N , McMullan W A 
Published: May 2021

Abstract
In this paper we perform large eddy simulations of variable density mixing layers, which originate from initially laminar conditions. The aim of this work is to capture the salient flow physics present in the laboratory flow. This is achieved through varying the nature of the inflow condition, and assessing the vortex structure present in the flow. Two distinct inflow condition types are studied; the first is an idealised case obtained from a mean inflow velocity profile with superimposed pseudo-white-noise, and the second is obtained from an inflow generation technique. The inflow conditions generated have matching mean and root mean squared statistics. Validation of the simulations is achieved through grid dependency and subgrid-scale model testing. Regardless of the inflow condition type used, the change in growth rate of the mixing layer caused by the density ratio is captured. It is found that the spacing of the large-scale spanwise structure is a function of the density ratio of the flow. Detailed interrogation of the simulations shows that the streamwise vortex structure present in the mixing layer depends on the nature of the imposed inflow condition. Where white-noise fluctuations provide the inflow disturbances, a spatially-stationary streamwise structure is absent. Where the inflow generator is used, a spatially stationary streamwise structure is present, which appears as streaks in plan-view visualisations. The stationary streamwise structure evolves such that the ratio of streamwise structure wavelength to local vorticity thickness asymptotes to unity, independent of the density ratio. This value is in agreement with previous experimental studies. Recommendations are made on the requirements of inflow condition modelling for accurate mixing layer simulations.
Tailoring a sub-diffraction optical focus via a straightforward interferometric approach
Authors: Neyra Enrique G , Vaveliuk Pablo 
Published: May 2021

Abstract
An approach for yielding light focuses below Abbe’s diffraction limit in Gaussian beams is presented. The method uses only standard passive optical elements as lenses, filters and mirrors and consists of a Michelson interferometric setup, where one of the light branches is modified in amplitude and/or phase. The focus narrowing process is carried out at the focal plane of a spherical lens by the interference of altered and unaltered light branches. The main focus features, namely, the focus intensity and size as well as the sidelobe intensity, are adjusted by varying two external parameters in a controllable manner under the conditions of pure destructive interference. Narrowing of the diffraction limit close to 40% with reduced intensity sidelobes (10%) is achieved. Due to the use of only lenses and mirrors, the approach does work with laser beams within a broad optical bandwidth ranging from infrared to ultraviolet in continuum regime as well as in ultra-short pulse regime. The method can also be implemented for high-power lasers and temporal domains. The focus-narrowing process emerges as a natural mechanism to the light interference, bringing a fresh perspective to applications from a few controllable degrees of freedom. The good performance of the sub-diffraction optical focus and the simplicity of the experimental setup promote new opportunities in fields ranging from optical manipulation of particles at sub-wavelength scale to optical writing and super-resolution microscopy.
Suspended graphene on germanium: selective local etching via laser-induced photocorrosion of germanium
Authors: Binder Johannes , Rogoza Jakub , Tkachenko Leonid , Pasternak Iwona , Sitek Jakub , Strupinski Wlodek , Zdrojek Mariusz , Baranowski Jacek M , Stepniewski Roman , Wysmolek Andrzej 
Published: May 2021

Abstract
The implementation of graphene in nanoelectromechanical systems and electronic applications requires not only techniques to fabricate high-quality monolayers, but also methods to process these layers. Nondestructive processing is especially challenging in the case of fragile suspended graphene membranes. In this work, we present a direct writing method for graphene grown on germanium that yields suspended layers without the need to transfer the graphene layer. To this end, we employ laser-induced photoelectrochemical etching which is highly selective and dissolves only germanium leaving the graphene layer intact. Only a focused continuous wave laser beam and water (or an aqueous solution) are required for the etching to proceed. Raman spectroscopy measurements were performed in-situ to monitor the etching process. These measurements reveal a dramatic increase of the graphene-related Raman bands as the graphene layer detaches from the substrate. This substantial increase indicates that the commonly observed weak Raman signal for graphene on germanium is not an inherent material property but is due to the interaction of the germanium substrate with graphene. Together with the established graphene growth on germanium, the presented direct writing method builds a complete toolbox for graphene membrane-based applications.
Plasmonic waveguides from Coulomb-engineered two-dimensional metals
Authors: Jiang Zhihao , Haas Stephan , Rösner Malte 
Published: May 2021

Abstract
Coulomb interactions play an essential role in atomically-thin materials. On one hand, they are strong and long-ranged in layered systems due to the lack of environmental screening. On the other hand, they can be efficiently tuned by means of surrounding dielectric materials. Thus all physical properties which decisively depend on the exact structure of the electronic interactions can be in principle efficiently controlled and manipulated from the outside via Coulomb engineering. Here, we show how this concept can be used to create novel plasmonic waveguides in metallic layered materials. We discuss how dielectrically structured environments can be utilized to non-invasively confine plasmonic excitations in an unperturbed homogeneous metallic two-dimensional system by modifications of its many-body interactions. We define optimal energy ranges for this mechanism and demonstrate plasmonic confinement within several nanometers. In contrast to conventional functionalization mechanisms, this scheme relies on a purely many-body concept and does not involve any direct modifications to the active material itself.