bluuebunny/crossref_metadata_2025 huggingface dataset:
Atmospheric CO2 Concentration and Other Limiting Factors in the Growth of C3 and C4 Plants
Authors: Boretti Albert , Florentine Singarayer
Published: April 2019

It has been widely observed that recent increases in atmospheric CO2 concentrations have had, so far, a positive effect on the growth of plants. This is not surprising since CO2 is an important nutrient for plant matter, being directly involved in photosynthesis. However, it is also known that the conditions which have accompanied this increase in atmospheric CO2 concentration have also had significant effects on other environmental factors. It is possible that these other effects may emerge as limiting factors which could act to prevent plant growth. This may involve complex interactions between prevailing sunlight and water conditions, variable temperatures, the availability of essential nutrients and the type of synthetic pathway for the plant species. The issue of concern to this investigation is if we should be worried about a possible shift in the C3-C4 paradigm driven by changes in the atmospheric CO2 concentration, or if some other factor, such as water scarcity, is much more relevant within a 30-year time frame. If an opinion is needed on what will have the worst effect on the survival of the planet between the scarcity of water or the reduced efficiency of C3 plants to sequester CO2, the issue of water is the more incisive.
Structure and Mechanical Performance of Poly(vinyl Alcohol) Nanocomposite by Incorporating Graphitic Carbon Nitride Nanosheets
Authors: He Shaojian , Wang Jiaqi , Yu Mengxia , Xue Yang , Hu Jianbin , Lin Jun
Published: April 2019

Owing to the high aspect ratio, the two-dimensional (2D) inorganic nanofillers have attracted extensive interest in the field of polymer reinforcement. In this work, graphitic carbon nitride (g-C3N4) nanosheets were obtained via thermal condensation of melamine and were then ultrasonically exfoliated in water, which was confirmed by atomic force microscopy (AFM) and TEM. Poly(vinyl alcohol) (PVA)/g-C3N4 nanocomposites were achieved by solution casting using water as the solvent. The structure and mechanical performance of PVA/g-C3N4 nanocomposites were studied. It was found that the g-C3N4 nanosheets were well dispersed in the PVA matrix. The introduction of g-C3N4 nanosheets increased the glass transition temperature and crystallinity of the nanocomposites, leading to the improved mechanical performance. Compared with the pure PVA, the PVA/g-C3N4 nanocomposite with 0.50 wt% g-C3N4 nanosheets showed ~70.7% enhancement in tensile strength, up from 51.2 MPa to 87.4 MPa.
Estimation of Mechanical Performance, Thermal Stability and Flame Retardancy of High-Impact Polystyrene/Surface-Modified APP/Carboxylic-Functionalized MWCNTs Nanocomposites
Authors: Ding Li , Jia Zhimeng , Sun Hao , Pan Yong , Zhao Jianping
Published: April 2019

An ammonium polyphosphate (APP) surface-modified by silane coupling agent was used as flame retardant in high-impact polystyrene (HIPS). A series of HIPS nanocomposites containing different mass fractions of APP (k-APP) surface-modified by silane coupling agent (3-aminopropyl triethoxysilane, KH 550) and carboxylic-functionalized MWCNTs (COOH–MWCNTs) were prepared by the melt blending method. A composite only containing APP was also prepared as a reference material. Scanning electron microscopy (SEM) was employed to investigate the dispersion of the fillers into the HIPS matrix, and it was found the hydrophobic groups on the k-APP surface would greatly enhance the dispersion and prevent agglomerations compared with APP. Furthermore, the COOH–MWCNTs also showed good dispersibility into the matrix. Mechanical tests of the nanocomposites revealed that k-APP exhibits a more beneficial effect on both tensile and flexural properties compared with APP. Thermogravimetric analysis (TGA) and cone calorimeter tests (CCT) were conducted to probe the thermal and flammability properties of the nanocomposites, respectively. The synergistic effects of k-APP and COOH–MWCNTs on mechanical, thermal and flammability properties were examined as well.
Preparation of Xylan-g-/P(AA-co-AM)/GO Nanocomposite Hydrogel and its Adsorption for Heavy Metal Ions
Authors: Kong Weiqing , Chang Minmin , Zhang Chunhui , Liu Xinxin , He Bei , Ren Junli
Published: April 2019

Xylan-g-/P(AA-co-AM)/Graphene oxide (GO) hydrogels were prepared and used in the removal of heavy mental ions. Acrylamide (AM), acrylic acid (AA), and xylan were used as the raw materials to prepare the hydrogels with ammonium persulfate (APS) as the initiator. The prepared hydrogels were characterized by Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), and energy dispersive X-ray (EDX). Some important properties of nanocomposite hydrogels such as swelling behavior, mechanical property, and adsorption capacity were also examined as well as the regeneration of the hydrogels. The results showed that the prepared hydrogels reached the equilibrium state of swelling after 12 h, and the compressive strength of the hydrogel with 30 mg of GO could reach up to 203 kPa. Compared with traditional hydrogel, the mechanical properties of the hydrogels with GO were obviously improved. The maximum adsorption capacity of hydrogels for Pb2+, Cd2+, and Zn2+ could reach up to 683 mg/g, 281 mg/g, and 135 mg/g, respectively. After five cycles of adsorption and desorption, the recovery rate of the hydrogels on Pb2+, Cd2+, and Zn2+ was still up to 87%, 80%, and 80%, respectively—all above 80%.
Synthesis and Characterization of 3-DOM IrO2 Electrocatalysts Templated by PMMA for Oxygen Evolution Reaction
Authors: Liu Fei , Sun Xuechu , Chen Xiu , Li Cuicui , Yu Jun , Tang Haolin
Published: April 2019

Three-dimensional ordered macroporous (3-DOM) IrO2 material was prepared using PMMA as a template and ammonia as a chelator. These 3-DOM IrO2 honeycomb arrays showed a large surface area and ordered macropores (155 nm in diameter) cross-linked by secondary mesopores. Internal structures of 3-DOM IrO2 material were observed microscopically through these secondary pores. According to the X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) spectra, 3-DOM IrO2 has a rutile crystal structure and is mainly composed of iridium dioxide. In acidic electrolytes, the overpotential of 3-DOM IrO2 material at 0.5 mV cm−2 was only 0.22 V. Accelerated durability tests demonstrated excellent durability of 3-DOM IrO2 as an oxygen evolution reaction (OER) catalyst.
Experimental Study of Micro Electrochemical Discharge Machining of Ultra-Clear Glass with a Rotating Helical Tool
Authors: Liu Yong , Zhang Chao , Li Songsong , Guo Chunsheng , Wei Zhiyuan
Published: April 2019

Electrochemical discharge machining (ECDM) is one effective way to fabricate non-conductive materials, such as quartz glass and ceramics. In this paper, the mathematical model for the machining process of ECDM was established. Then, sets of experiments were carried out to investigate the machining localization of ECDM with a rotating helical tool on ultra-clear glass. This paper discusses the effects of machining parameters including pulse voltage, duty factor, pulse frequency and feed rate on the side gap under different machining methods including electrochemical discharge drilling, electrochemical discharge milling and wire ECDM with a rotary helical tool. Finally, using the optimized parameters, ECDM with a rotary helical tool was a prospective method for machining micro holes, micro channels, micro slits, three-dimensional structures and complex closed structures with above ten micrometers side gaps on ultra-clear glass.
Optimal Strategies for Dengue Prevention and Control during Daily Commuting between Two Residential Areas
Authors: Lasluisa Daniel , Barrios Edwin , Vasilieva Olga
Published: April 2019

In this paper, we report an application for the mathematical theory of dynamic optimization for design of optimal strategies that account for daily commuting of human residents, aiming to reduce vector-borne infections (dengue) among human populations. Our analysis is based on a two-patch dengue transmission model amended with control variables that represent personal protection measures aimed at reduction of the number of contacts between mosquitoes and human hosts (e.g., the use of repellents, mosquito nets, or insecticide-treated clothing). As a result, we have proposed and numerically solved an optimal control problem to minimize the costs associated with the application of control measures, while also minimizing the total number of dengue-infected people in both residential areas. Our principal goal was to identify an optimal strategy for personal protection that renders the maximal number of averted human infections per unit of invested cost, and this goal has been accomplished on the grounds of cost-effectiveness analysis.
Simple Formulas for Pricing and Hedging European Options in the Finite Moment Log-Stable Model
Authors: Aguilar Jean-Philippe , Korbel Jan
Published: April 2019

We provide ready-to-use formulas for European options prices, risk sensitivities, and P&L calculations under Lévy-stable models with maximal negative asymmetry. Particular cases, efficiency testing, and some qualitative features of the model are also discussed.
Experience Prospective Life-Tables for the Algerian Retirees
Authors: Flici Farid , Planchet Frédéric
Published: April 2019

The aim of this paper is to construct prospective life tables adapted to the experience of Algerian retirees. Mortality data of the retired population are only available for the ages from 50 to 95 years and older and for the period from 2004 to 2013. The use of the conventional prospective mortality models is not supposed to provide robust forecasts given data limitation in terms of either exposure to death risk or data length. To improve forecasting robustness, we use the global population mortality as an external reference. The adjustment of the experience mortality on the reference allows projecting the age-specific death rates calculated based on the experience of the retired population. We propose a generalized version of the Brass-type relational model incorporating a quadratic effect to perform the adjustment. Results show no significant difference for men, either retired or not, but reveal a gap of over three years in the remaining life expectancy at age 50 in favor of retired women compared to those of the global population.
Improving Aboveground Forest Biomass Maps: From High-Resolution to National Scale
Authors: Durante Pilar , Martín-Alcón Santiago , Gil-Tena Assu , Algeet Nur , Tomé José Luis , Recuero Laura , Palacios-Orueta Alicia , Oyonarte Cecilio
Published: April 2019

Forest aboveground biomass (AGB) estimation over large extents and high temporal resolution is crucial in managing Mediterranean forest ecosystems, which have been predicted to be very sensitive to climate change effects. Although many modeling procedures have been tested to assess forest AGB, most of them cover small areas and attain high accuracy in evaluations that are difficult to update and extrapolate without large uncertainties. In this study, focusing on the Region of Murcia in Spain (11,313 km2), we integrated forest AGB estimations, obtained from high-precision airborne laser scanning (ALS) data calibrated with plot-level ground-based measures and bio-geophysical spectral variables (eight different indices derived from MODIS computed at different temporal resolutions), as well as topographic factors as predictors. We used a quantile regression forest (QRF) to spatially predict biomass and the associated uncertainty. The fitted model produced a satisfactory performance (R2 0.71 and RMSE 9.99 t·ha−1) with the normalized difference vegetation index (NDVI) as the main vegetation index, in combination with topographic variables as environmental drivers. An independent validation carried out over the final predicted biomass map showed a satisfactory statistically-robust model (R2 0.70 and RMSE 10.25 t·ha−1), confirming its applicability at coarser resolutions.
Estimation of Forest Structural Attributes Using Spectral Indices and Point Clouds from UAS-Based Multispectral and RGB Imageries
Authors: Shen Xin , Cao Lin , Yang Bisheng , Xu Zhong , Wang Guibin
Published: April 2019

Forest structural attributes are key indicators for parameterization of forest growth models, which play key roles in understanding the biophysical processes and function of the forest ecosystem. In this study, UAS-based multispectral and RGB imageries were used to estimate forest structural attributes in planted subtropical forests. The point clouds were generated from multispectral and RGB imageries using the digital aerial photogrammetry (DAP) approach. Different suits of spectral and structural metrics (i.e., wide-band spectral indices and point cloud metrics) derived from multispectral and RGB imageries were compared and assessed. The selected spectral and structural metrics were used to fit partial least squares (PLS) regression models individually and in combination to estimate forest structural attributes (i.e., Lorey’s mean height (HL) and volume(V)), and the capabilities of multispectral- and RGB-derived spectral and structural metrics in predicting forest structural attributes in various stem density forests were assessed and compared. The results indicated that the derived DAP point clouds had perfect visual effects and that most of the structural metrics extracted from the multispectral DAP point cloud were highly correlated with the metrics derived from the RGB DAP point cloud (R2 > 0.75). Although the models including only spectral indices had the capability to predict forest structural attributes with relatively high accuracies (R2 = 0.56–0.69, relative Root-Mean-Square-Error (RMSE) = 10.88–21.92%), the models with spectral and structural metrics had higher accuracies (R2 = 0.82–0.93, relative RMSE = 4.60–14.17%). Moreover, the models fitted using multispectral- and RGB-derived metrics had similar accuracies (∆R2 = 0–0.02, ∆ relative RMSE = 0.18–0.44%). In addition, the combo models fitted with stratified sample plots had relatively higher accuracies than those fitted with all of the sample plots (∆R2 = 0–0.07, ∆ relative RMSE = 0.49–3.08%), and the accuracies increased with increasing stem density.
Goaf Locating Based on InSAR and Probability Integration Method
Authors: Du Sen , Wang Yunjia , Zheng Meinan , Zhou Dawei , Xia Yuanping
Published: April 2019

Mining goafs can cause many hazards, such as burst water, spontaneous combustion of coal seams, surface collapse, etc. In this paper, a feature-points-based method for the efficient location of mining goafs is proposed. Different interferometric synthetic aperture radar (DInSAR) is used to monitor the subsidence basin caused by mining. Using the principles of the probability integral method (PIM), the inflection points and the boundary points of the basin monitored by DInSAR are determined and used as feature points to locate the goaf. In this paper, the necessity of locating goafs and the traditional methods used for this task are discussed first. Then, the results of verifying the proposed method by both a simulation experiment and real data experiment are presented. Six RADARSAT-2 images from 13th October 2015 to 5th March 2016 were used to acquire the subsidence basin caused by the 15235 working faces of the Jiulong mining area. The average relative errors of the simulation experiment and real data experiment were about 6.43% and 12.59%, respectively. The average absolute errors of the simulation experiment and real data experiment were about 28 m and 38 m, respectively. In the final part of this paper, the error sources are discussed to illustrate the factors that can affect the location result.
Scan Line Intensity-Elevation Ratio (SLIER): An Airborne LiDAR Ratio Index for Automatic Water Surface Mapping
Authors: Yan Wai , Shaker Ahmed , LaRocque Paul
Published: April 2019

Owing to the characteristics of how a laser interacts with the water surface and water column, the measured Light Detection and Ranging (LiDAR) intensity values are different with respect to the laser wavelength, the scanning geometry and the reflection mechanism. Depending on the instantaneous water condition and the laser incidence angle, laser dropouts can appear, causing null returns or empty holes found in the collected LiDAR data. This variable intensity response offers a valuable opportunity for using airborne LiDAR sensors for automatic identification of water regions, and thus, we previously proposed an airborne LiDAR-based ratio index named the scan line intensity-elevation ratio (SLIER). Over the water surface, airborne LiDAR data are always found to have a high fluctuation of the intensity value and low variation of the elevation along each scan line, and thus, the water region has a higher SLIER value compared to the land. We examined the SLIER on a multispectral airborne LiDAR dataset collected by Optech Titan and a monochromatic airborne LiDAR dataset collected by Optech Galaxy on a natural rocky shore and a man-made shore. Our experiments showed that SLIER was able to provide a high separability between land and water regions and was able to outperform the traditional normalized difference water index (NDWI) for estimation of the water surface. With the use of SLIER as a mechanism for training data selection, our case studies demonstrated an overall accuracy of 98% in the use of either monochromatic or multispectral LiDAR data, regardless of the laser channel being used.
A Secure Mutual Batch Authentication Scheme for Patient Data Privacy Preserving in WBAN
Authors: Konan Martin , Wang Wenyong
Published: April 2019

The current advances in cloud-based services have significantly enhanced individual satisfaction in numerous modern life areas. Particularly, the recent spectacular innovations in the wireless body area networks (WBAN) domain have made e-Care services rise as a promising application field, which definitely improves the quality of the medical system. However, the forwarded data from the limited connectivity range of WBAN via a smart device (e.g., smartphone) to the application provider (AP) should be secured from an unapproved access and alteration (attacker) that could prompt catastrophic consequences. Therefore, several schemes have been proposed to guarantee data integrity and privacy during their transmission between the client/controller (C) and the AP. Thereby, numerous effective cryptosystem solutions based on a bilinear pairing approach are available in the literature to address the mentioned security issues. Unfortunately, the related solution presents security shortcomings, where AP can with ease impersonate a given C. Hence, this existing scheme cannot fully guarantee C’s data privacy and integrity. Therefore, we propose our contribution to address this data security issue (impersonation) through a secured and efficient remote batch authentication scheme that genuinely ascertains the identity of C and AP. Practically, the proposed cryptosystem is based on an efficient combination of elliptical curve cryptography (ECC) and bilinear pairing schemes. Furthermore, our proposed solution reduces the communication and computational costs by providing an efficient data aggregation and batch authentication for limited device’s resources in WBAN. These additional features (data aggregation and batch authentication) are the core improvements of our scheme that have great merit for limited energy environments like WBAN.
State Transition for Statistical SLAM Using Planar Features in 3D Point Clouds
Authors: Gostar Amirali Khodadadian , Fu Chunyun , Chuah Weiqin , Hossain Mohammed Imran , Tennakoon Ruwan , Bab-Hadiashar Alireza , Hoseinnezhad Reza
Published: April 2019

There is a large body of literature on solving the SLAM problem for various autonomous vehicle applications. A substantial part of the solutions is formulated based on using statistical (mainly Bayesian) filters such as Kalman filter and its extended version. In such solutions, the measurements are commonly some point features or detections collected by the sensor(s) on board the autonomous vehicle. With the increasing utilization of scanners with common autonomous cars, and availability of 3D point clouds in real-time and at fast rates, it is now possible to use more sophisticated features extracted from the point clouds for filtering. This paper presents the idea of using planar features with multi-object Bayesian filters for SLAM. With Bayesian filters, the first step is prediction, where the object states are propagated to the next time based on a stochastic transition model. We first present how such a transition model can be developed, and then propose a solution for state prediction. In the simulation studies, using a dataset of measurements acquired from real vehicle sensors, we apply the proposed model to predict the next planar features and vehicle states. The results show reasonable accuracy and efficiency for statistical filtering-based SLAM applications.
Googling Fashion: Forecasting Fashion Consumer Behaviour Using Google Trends
Authors: Silva Emmanuel Sirimal , Hassani Hossein , Madsen Dag Øivind , Gee Liz
Published: April 2019

This paper aims to discuss the current state of Google Trends as a useful tool for fashion consumer analytics, show the importance of being able to forecast fashion consumer trends and then presents a univariate forecast evaluation of fashion consumer Google Trends to motivate more academic research in this subject area. Using Burberry—a British luxury fashion house—as an example, we compare several parametric and nonparametric forecasting techniques to determine the best univariate forecasting model for “Burberry” Google Trends. In addition, we also introduce singular spectrum analysis as a useful tool for denoising fashion consumer Google Trends and apply a recently developed hybrid neural network model to generate forecasts. Our initial results indicate that there is no single univariate model (out of ARIMA, exponential smoothing, TBATS, and neural network autoregression) that can provide the best forecast of fashion consumer Google Trends for Burberry across all horizons. In fact, we find neural network autoregression (NNAR) to be the worst contender. We then seek to improve the accuracy of NNAR forecasts for fashion consumer Google Trends via the introduction of singular spectrum analysis for noise reduction in fashion data. The hybrid neural network model (Denoised NNAR) succeeds in outperforming all competing models across all horizons, with a majority of statistically significant outcomes at providing the best forecast for Burberry’s highly seasonal fashion consumer Google Trends. In an era of big data, we show the usefulness of Google Trends, denoising and forecasting consumer behaviour for the fashion industry.
Effects of Short Practice of Climbing on Barriers Self-Efficacy within a Physical Education and Sport Intervention in Germany
Authors: Krüger Mirko , Seng Christiane
Published: April 2019

The study examined the effects of an indoor wall climbing intervention within the context of a regular Physical Education and Sport (PES) program on barriers self-efficacy (SE) of adolescents in Germany. The study used a field experiment with a wait-list control group. Seventy-eight 8th-graders were included (age: 14.41 ± 0.71 years), with 37 randomly assigned for the intervention group and 41 for the control group. The intervention group participated in two half-day indoor wall climbing excursions (duration: 180 min each) based on SE building strategies. Both groups were pre-and post-tested in SE of indoor wall climbing and belaying. The control group did not receive any treatment before post-test. After the intervention, significant improvements were found in the experimental group on SE of belaying (F(1,76) = 23.45, p = 0.000, η2p = 0.24) using repeated-measures ANOVA. This study provides the first evidence from a German PES field experiment on increasing an important SE facet related to indoor wall climbing among 8th-graders. The program may be improved and further analyzed to install a short-term method to achieve one important educational goal within ordinary PES programs in Germany and to contribute to the personal development of the students.
Assessing the Impact of School Rules and Regulations on Students’ Perception Toward Promoting Good Behavior: Sabian Secondary School, Dire Dawa, Ethiopia
Authors: Fekadu Alemneh Amesalu
Published: April 2019

Discipline is an important component of human behavior, and one could assert that without it, an organization cannot function well toward the achievement of its goals. The aim of this study was to assess the impact of school rules and regulations on students’ perception toward promoting good behavior. The data were obtained from 438 respondents through a mailed questionnaire instrument. The data were tabulated, and Pearson’s chi-square test was applied for inferential analysis. Around 33.1% of the students had a negative perception of school rules and regulations about promoting good behavior, whereas 66.9% of them had a positive perception. A p-value of 0.015 (<5% significance level) indicated that there is a significant association between students’ awareness on school rules and regulations and their perception toward promoting good behavior. Students’ attitudes on school rules and regulations and perception toward promoting good behavior were statistically associated at a p-value of 0.012. Parents’ educational levels had a significant effect on students’ perception toward promoting good behavior. Generally, students’ awareness on school rules and regulations, parents’ education levels, civics and ethical education scores, and students’ attitudes toward promoting good behavior were found as significant effects on perception toward promoting good behavior.
The Marceño Agroecosystem: Traditional Maize Production and Wetland Management in Tabasco, Mexico
Authors: Peraza-Villarreal Humberto , Casas Alejandro , Lindig-Cisneros Roberto , Orozco-Segovia Alma
Published: April 2019

The marceño agroecosystem is based on traditional agriculture in the flooded areas of the alluvial plains of Tabasco, Mexico. In the marceño system, the native maize, called “mején”, is cultivated during the dry season using residual soil moisture. At physiological maturity, mején is tolerant to flooding. To estimate the potential area where marceño may be implemented, we characterized and defined the areas where it is practiced, using geographic information systems (GIS), and determined the bioclimatic variables of the sites where 16 species of wild plants associated with the management of the marceño grow. We also analysed areas of agriculture and livestock in relation to the cyclical floods. This information was used to generate a probability model of marceño occurrence through MaxEnt, which was superimposed on an elevation model (LiDAR) geoprocessed with GIS. The marceño was observed in 203 localities across eight municipalities of Tabasco (~2% of the state area), at elevations of 1–7 m. The calculated area with potential for implementation of the marceño is about 18.4% of the state area. The implementation of this agroecosystem on a wider area might be an alternative for local agriculture development and a strategy for ecological conservation and restoration of wetlands.
Real Estate Industry as an Urban Growth Machine: A Review of the Political Economy and Political Ecology of Urban Space Production in Mexico City
Authors: Delgado Ramos Gian Carlo
Published: April 2019

Cities concentrate the means of production, wealth, political power, infrastructure, educational institutions, and a relevant share of our cultural heritage. As such, they are seen as places of opportunities. Contemporary urbanization, however, being central to the accumulation of capital, has also escalated environmental problems that are usually suffered by the urban poor due to an uneven production of urban space. Mexico City is not an exception. It has mainly expanded through a lively auto-construction process and, more recently, under the incentive of a speculative urban development. The first trend reinforces the informal housing sector, in certain cases, involving significant environmental implications such as the degradation of land of ecological value. The second trend responds to capital accumulation dynamics, promoting urban renewal in central areas or where a greater potential rent-gap exists, underpinning the uneven production of urban space, and usually withholding most of its related socioenvironmental impacts. This paper focusses on this second process. It assesses the so-called “urban growth machine” in action, its socioecological impacts, and related contestation processes. With that in mind and after a general introduction and a brief description of urban development in Mexico, the real estate industry in Mexico City is evaluated in terms of the potential ecological implications of the building stock expansion from 2012 to 2018. A spatial distribution analysis of contestation processes, correlated to such urban expansion, is presented as well. The case study confirms what has been learned in other locations of the Global South, where a contradictory and uneven process of urban development has also been experienced under the stimulus of capital speculation. The paper, however, offers a novel approach by bringing together urban political economy, industrial ecology and urban political ecology analytical tools. Such hybridization, it is argued, enables a more comprehensive understanding of contemporary urbanization and its socioenvironmental impacts, which in turn is central to any effort for urban transformation.
Interpretive Structural Model Based Factor Analysis of BIM Adoption in Chinese Construction Organizations
Authors: Ma Guofeng , Jia Jianyao , Ding Jiyong , Shang Shanshan , Jiang Shan
Published: April 2019

The adoption of Building Information Modeling (BIM) will definitely improve the efficiency and quality of the AEC (architecture, engineering and construction) industry. However, many factors need to be improved before BIM adoption. Based on the interaction between institutions and technology, factors affecting BIM adoption in AEC organizations, within the context of China, are identified and analyzed. Firstly, 21 factors are identified by literature research. Then, an interpretive structural model (ISM) technique is used to establish a hierarchical structure, and matrix impacts cross-reference multiplication applied to a classification (MICMAC) is used for factor classification. The results indicate that corporate/project leadership and software functionality are the two fundamental factors. What’s more, the dynamic mechanism has gradually changed from top-down to a combination of top-down and bottom-up.
Human Health and Well-Being in Relation to Circular and Flexible Infill Design: Assessment Criteria on the Operational Level
Authors: Geldermans Bob , Tenpierik Martin , Luscuere Peter
Published: April 2019

This paper addresses the connection between circular building design and residential health and well-being. The general research objective is to determine assessment criteria for the performance of indoor partitioning products in a circular model. The overarching aim is to establish a more integrated and inclusive approach to the transition from linear to circular built environments. This ties in with recent calls for a more comprehensive evidence-base to better inform the policy debate, in the light of interrelated Sustainable Development Goals. The paper emphasises the operational level, looking closer at the actual performance of circular economy implementation, providing more grip on performance indicators of infill components in circular applications, specifically partition walls. Next to partitioning one can think of other components in the infill domain, such as kitchens, bathrooms and mechanical, electrical, plumbing installations. After a brief background sketch, a literature review is reported regarding indoor environmental quality and indoor air quality in general and the linkage with circular and flexible building (products) in particular. Next, an analysis is made of three assessment schemes that address the operational level. Subsequently, several criteria are synthesized and tested. It was shown that the assessment schemes have overlapping and complementary features that, in unison, provide a solid basis for an integrated assessment of circularity potential and health impact of infill products. The test-case helped to pinpoint generic, as well as case-specific, learning points. The interface between product performance and building performance over time remains a grey zone, insufficiently covered by current criteria. More stringent coordination efforts are essential to safeguard circularity potential and healthy living environments pre-use, post-use and not least in-use.
Multilevel Governments’ Decision-Making Process and Its Influencing Factors in Watershed Ecological Compensation
Authors: Gao Xin , Shen Juqin , He Weijun , Sun Fuhua , Zhang Zhaofang , Zhang Xin , Yuan Liang , An Min
Published: April 2019

Transboundary water pollution is a long-standing problem in China, although the Chinese government has been committed to the protection of water resources. Due to the different interests of multilevel governments and the regionalization of management, there is still no unified plan to solve the transboundary water pollution in China. Watershed ecological compensation as a holistic plan to deal with transboundary water pollution is being promoted currently. Taking the South-to-North Water Transfer Project’ eastern route as an example, this paper firstly analyses stakeholders’ strategies and establishes a tripartite game model based on evolutionary game theory. Secondly, by introducing Cobb Douglas production function creatively, the supervision level of the central government is refined into supervisory attitude and supervisory skills. Thirdly, the numerical simulation is used to analyze the sensitivity of influencing factors. The results show that: (1) whether the central government supervises the local governments mainly depends on the benefits of water environment improvement and supervision costs; (2) the initial negotiation plan of the stakeholders has a significant impact on their optimum strategies; (3) the fines imposed by the central government on the local governments have a small impact on the stable state of the system; (4) the higher the eco-compensation fee, the lower their likelihood of cooperation; (5) the central government’s supervisory attitude and supervisory skills have significant effect on the sustainability of the optimum arrangement, even when willingness of upstream and downstream governments to cooperate is low; (6) the initial ecological benefits of downstream governments have no effect on the optimum strategy. Therefore, considering these insights is helpful to improve the watershed ecological compensation mechanism in order to solve transboundary water pollution and achieve the sustainability of water resources.
Socio-Economic Viability of Urban Agriculture—A Comparative Analysis of Success Factors in Germany
Authors: Krikser Thomas , Zasada Ingo , Piorr Annette
Published: April 2019

Socio-economic viability of urban agriculture (UA) is, especially regarding non-commercially oriented initiatives, at most a generically treated issue in scientific literature. Given a lack of data on yields, labor input, or saved expenditures, only a few studies have described it either from a cost-avoidance or a specific benefit generation perspective. Our hypothesis is that hybrid roles of consumers and producers in urban agriculture challenge the appraisal of socio-economic viability. This paper presents an empirical study from three prevalent urban agriculture models: self-harvesting gardens, intercultural gardens, and community gardens, combining qualitative and quantitative survey data. A multi-value qualitative comparative analysis was applied to grasp the perception of socio-economic viability and its success factors. This allowed us to identify necessary and sufficient conditions for economic and social success. Results give an indication of the existence of different value systems and cost–benefit considerations in different urban agriculture models. A service-focused business relationship between farmers and consumers ensuring self-reliance is important for success for self-harvesting gardens, while self-reliance and sharing components are relevant for intercultural gardens. Community gardening builds upon self-governance ambitions and a rather individually determined success and failure factor pattern beyond explicit production output orientation. It is shown here for the first time with a quantitative approach that participants of urban agriculture models seem to go beyond traditional trade-off considerations and rather adopt a post-productive perception, focusing more on benefits than costs.
Innovation, Mark-Up and Firm Growth: Evidence from China’s New Generation IT Industry
Authors: Li Hongya , Jin Laiqun , Ding Yuanyao
Published: April 2019

In this paper, we provide empirical evidence for understanding the growth behavior of China’s new generation of information technology (IT) industrial firms and the impact of innovation and market power on them. Based on the data of China’s new generation IT industrial firms covering the period 2000–2007, we use ordinary least square (OLS) and two-stage least squares (IV-2SLS) methods to study the effects of innovation and markup on the growth of China’s new generation IT industrial firms in the framework of Gibrat’s law. IV-2SLS estimations show that: (1) Innovation and markup have positive and significant effects on the firm’s total revenue growth rate, but have no significant or negative effects on the growth rate of the firm’s total assets and employment. (2) Innovation has a positive and significant effect on the firm’s mark-up. The results indicate that for China’s new generation IT industrial firms which are technology-intensive, improving the technological innovation and market power will reduce the firm’s input and increase the firm’s output. Innovation can significantly increase the firm’s mark-up. (3) From the perspective of the dynamic evolution of a firm’s growth, firm size has a negative and significant impact on the firm growth while firm age has a positive and significant impact on the firm’s growth. In addition, we also examine the different effects of capital intensity and export demand on the firm’s growth.
Characteristics of Residential Space in Response to Changed Lifestyles: Focusing on the Characteristics of Residents and the Relationship between Individual and Family
Authors: Kwon Hyun-ah , Kim Soomi
Published: April 2019

The housing type of apartments, which has been spreading widely in South Korea, has penetrated deep into the domestic housing culture, thanks to the advantage of “convenience” resulting from the mass production of industrial capitalism that prioritizes functionality and efficiency. However, as capitalist social structures undergo transformation, in the 21st century, under a paradigm emphasizing creativity over functionality and efficiency, the characteristics of everyday life are also changing. Therefore, this study focuses on newly emerging lifestyles resulting from this transition of social structures. It analyzes the characteristics of residential space that reflect this trend, centering on “the characteristics of residents” and “the relationship between individual and family”. To this end, we compared lifestyle magazines aimed at the general public and architectural magazines aimed at architectural experts. Section 3 explores the changed lifestyles of residents by analyzing the articles containing interviews with residents in lifestyle magazines, while Section 4 focuses on the characteristics of residential spaces in reflecting these changes by analyzing houses and articles of architects and critics in architectural magazines. This analysis consistently brought forth the question of the limit of existing spaces of apartments and the desire to overcome them. A correspondence between residential spaces and the needs of everyday lives and lifestyles is a basic requirement for sustainable housing. Thus, the design of residential spaces will have to begin with a clear understanding of residents and their lifestyles, which can then be mapped onto the characteristics of residential spaces that can support them.
Analysis of a CO2 Transcritical Refrigeration Cycle with a Vortex Tube Expansion
Authors: Liu Yefeng , Sun Ying , Tang Danping
Published: April 2019

A carbon dioxide (CO2) refrigeration system in a transcritical cycle requires modifications to improve the coefficient of performance (COP) for energy saving. This modification has become more important with the system’s more and more widely used applications in heat pump water heaters, automotive air conditioning, and space heating. In this paper, a single vortex tube is proposed to replace the expansion valve of a traditional CO2 transcritical refrigeration system to reduce irreversible loss and improve the COP. The principle of the proposed system is introduced and analyzed: Its mathematical model was developed to simulate and compare the system performance to the traditional system. The results showed that the proposed system could save energy, and the vortex tube inlet temperature and discharge pressure had significant impacts on COP improvement. When the vortex tube inlet temperature was 45 °C, and the discharge pressure was 9 MPa, the COP increased 33.7%. When the isentropic efficiency or cold mass fraction of the vortex tube increased, the COP increased about 10%. When the evaporation temperature or the cooling water inlet temperature of the desuperheater decreased, the COP also could increase about 10%. The optimal discharge pressure correlation of the proposed system was established, and its influences on COP improvement are discussed.
Enhanced Community Production rather than Structure Improvement under Nitrogen and Phosphorus Addition in Severely Degraded Alpine Meadows
Authors: Zong Ning , Shi Peili
Published: April 2019

Fertilization is a common management measure for the restoration of degraded grasslands. In order to investigate whether fertilization can improve the severely degraded alpine meadows, we conducted a fertilization experiment on the Tibetan Plateau that began in 2008. The treatments were nitrogen (N) addition alone (50 kg N ha−1 year−1, LN; 100 kg N ha−1 year−1, HN) or combined with phosphorus (P) fertilizer [(50 kg N + 50 kg P) ha−1 year−1, LN+P; (100 kg N + 50 kg P) ha−1 year−1, HN + P] in a severely degraded alpine meadow. Eleven consecutive years of N and P fertilization did not significantly change plant species richness, while fertilization reduced the plant species diversity index, with the most significant reduction in HN and HN + P treatments. LN + P and HN + P treatments greatly increased community coverage and aboveground biomass, while N addition alone, especially the HN treatment, significantly reduced community coverage and aboveground biomass. Fertilization had no effect on edible pastures, while N and P fertilization significantly increased the biomass of forbs. The proportion of forbs to total aboveground biomass was more than 90%, and fertilization had no effect on this proportion. This shows that forbs still have an absolute advantage in the community. In addition, HN, LN + P, and HN + P treatments significantly reduced ecosystem stability. Community aboveground biomass was greatly enhanced in the N and P fertilization treatments, and this was beneficial for the ecosystem quality and soil hydrological functioning. However, fertilization treatments did not improve the community structure with either N addition alone or combined with P fertilizer, which was of little significance in providing forages for the sustainable development of livestock husbandry. To improve the structure of severely degraded alpine grasslands, it is necessary to combine other measures such as cutting the roots of forbs, fencing, or reseeding.
Bernoulli’s Problem for the Infinity-Laplacian Near a Set with Positive Reach
Authors: Greco Antonio
Published: April 2019

We consider the exterior as well as the interior free-boundary Bernoulli problem associated with the infinity-Laplacian under a non-autonomous boundary condition. Recall that the Bernoulli problem involves two domains: one is given, the other is unknown. Concerning the exterior problem we assume that the given domain has a positive reach, and prove an existence and uniqueness result together with an explicit representation of the solution. Concerning the interior problem, we obtain a similar result under the assumption that the complement of the given domain has a positive reach. In particular, for the interior problem we show that uniqueness holds in contrast to the usual problem associated to the Laplace operator.
Near-Integrability of Periodic Klein-Gordon Lattices
Authors: Christov Ognyan
Published: April 2019

In this paper, we study the Klein-Gordon (KG) lattice with periodic boundary conditions. It is an N degrees of freedom Hamiltonian system with linear inter-site forces and nonlinear on-site potential, which here is taken to be of the ϕ 4 form. First, we prove that the system in consideration is non-integrable in Liouville sense. The proof is based on the Morales-Ramis-Simó theory. Next, we deal with the resonant Birkhoff normal form of the KG Hamiltonian, truncated to order four. Due to the choice of potential, the periodic KG lattice shares the same set of discrete symmetries as the periodic Fermi-Pasta-Ulam (FPU) chain. Then we show that the above normal form is integrable. To do this we use the results of B. Rink on FPU chains. If N is odd this integrable normal form turns out to be KAM nondegenerate Hamiltonian. This implies that almost all low-energetic motions of the periodic KG lattice are quasi-periodic. We also prove that the KG lattice with Dirichlet boundary conditions (that is, with fixed endpoints) admits an integrable, nondegenerate normal forth order form. Then, the KAM theorem applies as above.
Coreness Variation Rule and Fast Updating Algorithm for Dynamic Networks
Authors: Gao Liang , Gao Ge , Ma Dandan , Xu Lida
Published: April 2019

Coreness is one of the important indicators to measure the importance of a node. Traditionally, the coreness of a node is measured by k-core decomposition. However, to measure the coreness in a dynamic network, the k-core decomposition method becomes very time-consuming and inefficient, and cannot meet the need in very large real networks. Recently, the H operator method was proposed to calculate the coreness of a node, which provides a novel method to deal with the coreness of a node in a network. In this paper, we decode the coreness variation rule by a symmetric pair of experiments, i.e., deleting and adding edge, on real networks. Then, an algorithm to fast update the coreness of related nodes is proposed. Results on five real networks showed that the performance of the proposed algorithm was greatly enhanced and comprehensively superior to the k-core decomposition algorithm. Our study provides a promising way to optimize the algorithm of coreness calculation in the dynamic networks.