bluuebunny/crossref_metadata_2025_split huggingface dataset:
Performance analysis of Mixed MUD-RF/Multi-aperture FSO Relay Communication System with Co-channel Interference
Authors: Liu Wen-ya , Wang Xiang , Zhao Shang-hong 
Published: February 2021

Abstract
This paper discusses the performance of an improved dual-hop mixed radio frequency (RF) / free space optical (FSO) relay communication system in the present of multiple co-channel interferences (CCIs) at the relay node. Multi-user diversity(MUD) technology has been adopted to improve the RF link performance. In order to improve the performance of the FSO link, multi-aperture receiver scheme has been implemented. The multi-user RF link experiences Nakagami-m fading, while the FSO link is subjected to Exponentiated Weibull distributed atmospheric turbulence. Moreover, the CCIs at the relay node are assumed to undergo Nakagami-m fading. For this proposed system, the exact closed-form expression for the outage probability (OP) has been derived. To quickly understand the effects of different parameters on the system performance, the asymptotic expression for the case of high signal-to-noise (SNR) has been further presented. Results show that the diversity order of this proposed system is min (αβM/2,m
1
K), where M represents the number of receiver apertures; K denotes the number of users; α, β and m
1 are the channel parameters. Additionally, the effects of various parameters on system performance have been investigated. Finally, the numerical results have been validated by Monte-Carlo simulations.
Low Cost and Large Bandwidth Visible Light Communication System Design
Authors: Zhang Ziming , Wang Xichen , Wu Qian , Liu Yuanqin 
Published: February 2021

Abstract
Aiming at the problem of insufficient bandwidth of transmitter and receiver of low-cost visible light communication system, this article applies novel-equalization circuits to separately expand the bandwidth of LED and transimpedance amplifier circuit to 114MHz and 95.7MHz. In addition, signal-to-noise ratio and bit error rate of the system are also analyzed by a line of sight model and the feasibility of the designed system is confirmed.
A Study on the EDA-based Classification of News Text
Authors: Shuwei Xu , Xuyang Gao , Ying Wang 
Published: February 2021

Abstract
At present, the commonly used word vector methods for news text classification mostly adopt Word2Vec, Glove, Bert and other word vector models, ignoring the remote context connections of Chinese text itself. TextCNN, RNN, BiLSTM and other neural network classification models lack the extraction of important information features of the text, and the word dependence inside the text is not strong, resulting in inaccurate classification results. To solve the above problems, this paper proposes the DPCNN-Attention news text classification model based on ERNIE’s pre-training model(EDA for short, the following general). The DPCNN neural network model with Mish() activation function is adopted to obtain the maximum length of semantic association between long distance texts in news texts. By adding attention mechanism into EDA model, in the feature extraction process, according to the importance of words to the classification results, different weights are assigned to them to enhance the word dependence relationship within the text, thus greatly improving the classification accuracy. The EDA model was experimentally verified on the THUCNews dataset. The results showed that the EDA model improved by about 6% compared with BERT’s pre-training model, and 0.4% compared with ERNIE’s pre-training model. The loss rate decreased by 0.2 compared with BERT and 0.01 compared with ERNIE’s.
Research on Generation Methods of Test Cases for Pair-wise Covering Combinatorial Test Cases
Authors: Dandan He , Yue Zhai , Lijuan Wang 
Published: February 2021

Abstract
For most software systems, pair-wise combinatorial testing is highly practical and effective. This article mainly starts with the specific research status of the pair-wise covering combinatorial test and the main content of the software test, analyzes and compares the existing main implementation algorithms, and then evaluates their specific performance.
Systematic assessment of food security by recurrent addition of fuzzy cognitive maps
Authors: Rogachev A F 
Published: February 2021

Abstract
The results of an analytical review of the problems of modeling the state and evolution of socio-economic systems solved using the mathematical apparatus of matrix analysis of cognitive maps are presented. The difference between classical and fuzzy cognitive maps (FCM) is shown. The problems, strengths and weaknesses of algorithms and tools for assessing the level of food security (FS) based on a fuzzy cognitive approach are considered. The basic groups of concepts and methods for constructing the FCM that provide a fuzzy integral assessment of the PB level are analyzed. A method of recurrent construction of the NCC by successive addition of a set of concepts is proposed. In the process of adding concepts, experts make step-by-step recurrent adjustments to the values of the mutual influence of concepts. Recommendations for justification are presented, using the example of assessing the level of FS, the choice of tools for building the NCC. The solution of the problem of assessing the level of regional FS is illustrated for a set of economic, environmental and organizational concepts. It is shown that for adjusting the para-meters generated by the FCM, including to take account of their changes over time require the creation of software tools for fuzzy cognitive modeling, taking into account specific tasks and retrospective information together with simulated system factors.
Agricultural crops programmed cultivation using intelligent system of irrigated agrocoenoses productivity analyzing
Authors: Tokarev K E 
Published: February 2021

Abstract
The article considers the possibilities of controlling the programmed cultivation of agricultural crops using an intelligent system for analyzing the productivity of irrigated agrocoenoses. The information support of the intelligent system is standard information about agrometeological conditions, technical parameters of irrigation systems and irrigation machines, as well as information about the amount of water resources allocated for irrigation. The obtained results provide a strict theoretical basis for solving the issues of irrigation water distribution and operational management of the irrigation regime, clarify and simplify the procedure for choosing the optimal variant of the irrigation system design solution, and make it possible to make reasonable decisions related to the rational use of water resources in existing systems.
Raising bio-productivity of agroecosystems using intelligent decision-making procedures for optimization their state management
Authors: Tokarev K E 
Published: February 2021

Abstract
The article deals with the problems of increasing the bio-productivity of agroecosystems with the help of intelligent decision-making procedures to optimize the management of their state. In the course of research, the author developed an algorithm for the interaction of operational and planned. Management of the state of the agroecosystem, characterized in that the values of the controlled parameters change due to changes in the initial formulation of the optimization problem and the actual content of humus at the beginning of rotation. This allows you to manage the state of the agroecosystem, taking into account the need to restore humus. In addition, the author proposes a method and algorithm for decision support system for managing the state of the agroecosystem, which allows to rationalize the process of fertilization, to ensure an increase in crop yields, profitability of agricultural production and preservation of soil fertility. With the help of decision support system (DSS), the conditions for preserving soil fertility (variants of applied mineral and organic fertilizers that stabilize humus) were determined and forecasts of bio-productivity and economic efficiency.
Contrast Limited Adaptive Histogram Equalization for Underwater Image Matching Optimization use SURF
Authors: Suharyanto  , Hasibuan Z A , Andono P N , Pujiono D , Setiadi R I M 
Published: February 2021

Abstract
Conditions of the underwater environment have its challenges in the underwater vision research process. Some things that make underwater imagery difficult is that light can be scattered by particles in the sea, besides that light can be absorbed by seawater, as well as the turbidity level of seawater, so special techniques are needed to get clear underwater imagery. In underwater environmental conditions, the images obtained are usually of very poor quality. Backlight and attenuation will occur this is due to water conditions, objects that dissolve easily in water, and other particulate matter so that there is the degradation of the underwater image. Because it is very important if the image is improved in quality to facilitate the process of describing objects. Image matching techniques to determine the key points of image pairs are needed in three-dimensional reconstruction research. Speeded Up Robust Features (SURF) is an image matching technique where the matching results are very dependent on the image quality. This study proposes the Contrast Limited Adaptive Histogram Equalization (CLAHE) method to increase the number of matching images with SURF. The results of the experiment showed that image matching increased by an average of 76,8 %.
Mechanical Properties and Morphological Characterisation of Waste Natural Fiber Composites Reinforced Polyester: Gelam (Melaleuca Leucadendra)
Authors: Laksono A D , Ismail I , Ningrum C R , Sulistijono  , Ernawati L 
Published: February 2021

Abstract
The mechanical (tensile, flexural, and impact) tests and morphology observation were investigated on Natural Fiber Composites (NFCs) formed by strengthening Gelam as a fiber into the polyester as a resin matrix. The samples were prepared up to a maximum volume fraction of 0.70 from the fibers in powder form, hand lay-up method, and compared with pure Gelam and pure polyester. The synthesis results indicate for adding Gelam fiber in volume fraction that the optimum composition is at the addition of 0.70 fiber, with a tensile strength of 14.77 MPa, bending strength of 53.12 MPa, and the impact strength of 755.48 MPa. It was investigated that the impact strength and tensile strength of Gelam-polyester composite increase compare to pure Gelam. However, the result of flexural strength is decreased that can be associated with many factors such as incompatibility between matrix and fiber, instability of the hand lay-up method.
The impact of modern construction technology on the workforce in the construction industry
Authors: Agenbag H , Amoah C 
Published: February 2021

Abstract
This study investigated the impact of the use of construction technology equipment on the workforce in the construction industry. This study made use of the quantitative approach. Questionnaires were sent out to construction industry professionals, such as project managers, quantity surveyors, engineers, and owners of construction companies. Data received was analysed using descriptive statistics. The findings reveal that the use of construction equipment will have a tremendous impact on the workforce as one equipment would be able to execute work that could be done by a sizeable number of labourers. It was also found that the productivity of construction projects in South Africa can be increased by making use of construction technology equipment. However, it will be a herculean task to fully adopt construction technology equipment in project execution in South Africa as respondents believe the construction industry is heavily relied upon by the government to generate employment. There is also a perceived lack of expertise and lack of knowledge regarding the use of construction technology equipment among the workforce in the construction industry of South Africa. It is therefore suggested that construction companies invest in these different equipment, which will surely assist labourers and also speed up construction projects. The government must also look for areas of the economy to create jobs instead of relying heavily on the construction industry.
The structural characteristics of waste tire chars at different pyrolysis temperatures
Authors: Ren Qiangqiang , He Limo , Hu Song , Su Sheng , Wang Yi , Jiang Long , Xiang Jun 
Published: February 2021

Abstract
Pyrolysis was a promising technology to achieve waste tire (WT) dispose and utilization. However, large quantities of low quality waste tire chars (WTCs) would remain after pyrolysis and they could be employed to various applications. Further understanding the structural characteristics of WTCs at different pyrolysis temperatures would benefit to guide their utilizations. Herein, pyrolysis experiments were systematically conducted at 400 °C, 600 °C, 800 °C, and 1000 °C respectively to collect WTCs, whose structural characteristics were detailed analyzed. It was found that higher temperature can promote decrease of large and small aromatic ring systems, alkyl-aryl C-C bonds, defects with ordered arrangements of carbon skeleton structure. Pyrolysis can significantly promote pores formation, higher temperature would promote formation of micropores, while mesopores+macropores destroy before 600 °C and then gradually form. Higher temperature can promote decomposition of pyrrolic nitrogen and sulfur bridge with enrichment of oxidised nitrogen and sulphone bridge. Higher temperature would assist in generation of pyridinic nitrogen before 800 °C and quaternary nitrogen before 600 °C.
Advances in Urban River Landscape Ecology Research
Authors: Xu Surong 
Published: February 2021

Abstract
It is an inevitable trend to realize the sustainable development of “natural-human-water” through multi-scale and multi-disciplinary research on urban rivers with the principle of landscape ecology. Firstly, from the viewpoint of landscape ecology, and combined with the characteristics of urban rivers, the paper puts forward urban river landscape ecological theory and research framework. Secondly, the basic problems of urban river landscape ecology are studied. Finally, the theoretical development of urban river landscape ecology is studied, including the theory of urban river landscape ecosystem complexity, classification method of wetland and riverine ecosystem, and modeling of patch age and heteromorphosis. The research results have certain reference value for ecological river construction and river landscape ecology development.
Adsorption of Cd (II) Ions by Coconut Copra: Isotherm and Regeneration Studies
Authors: Lee Terri Zhuan Ean , Zhang Jianghong , Feng Yichen , Lin Xin , Zhou Jinqin 
Published: February 2021

Abstract
This study employed coconut copra to adsorb cadmium and investigated its adsorption behavior via isotherm models. A total of seven isotherm models, namely Langmuir, Freundlich, Sips, Temkin, Dubinin-Radushkevic, Brouers-Sotolongo and Hill were utilized to investigate the adsorption mechanism. Results showed that Langmuir isotherm best fitted cadmium adsorption process among all models studied, with correlation coefficient, R2 of 0.963. The maximum adsorption capacity of coconut copra towards cadmium recorded 1.092 mg g−1 according to Langmuir isotherm, Dubinin-Radushkevic and Temkin isotherm asserted that this is a physical adsorption process. This study however observed negative cooperativity, as claimed by Hill and Temkin isotherm models. In addition, this study explored the feasibility of biosorbent regeneration. Coconut copra demonstrated potential to be regenerated, supported by its efficient removal percentage up to 7 consecutive adsorption-desorption cycles. As a whole, coconut copra is potentially viable to be used as a sustainable biosorbent for cadmium removal cadmium.
Mechanical properties of M-Zr (M=Cr, Al, Mn) co-doped ceria: A first-principles study
Authors: Xiao Wei , Shi Jingmin , Sun Lu , Wang Xue , Zhou Gege , Yan Jiasi 
Published: February 2021

Abstract
Zr-doped ceria has been extensively been used in three-way catalyst industry due to the excellent physical and chemical properties. Co-doping technology is always employed to improve the stability of the materials by hindering the phase segregation into CeO2 and ZrO2 individual phases. In this paper, we have intensively studied the stability of M-Zr co-doping systems (M= Cr, Al and Mn) under different growth conditions and under the applied stress. The results show that the O-rich growth condition is very beneficial to the formation of these compounds. Compared with Cr and Mn atoms, Al atoms produce a different type of lattice distortions, which all can improve the stability of the whole system. Among these candidates, Al-Zr co-doping can be most easily formed. Furthermore, our researches demonstrate that under a small strain range, co-doping might increase the mechanical properties of the systems by the solid solution strengthening.
Application Characteristics and Industrial Development Countermeasures of Shenmu Semi-coke
Authors: Wei Ning , Wang Lidan , Zhao Bo , Yan Qingcong 
Published: February 2021

Abstract
The quality index of Shenmu semi-coke is investigated to study its application characteristics, combined with the quality index of Shenmu raw coal and anthracite. Through the analysis of semi-coke products and the environmental protection characteristics in the production process, the ideas for cleaner production are provided. The industrial development countermeasures are put forward based on the development and future demand of Shenmu semi-coke industry.
Research on the market mechanism of generation grid load storage interaction to promote new energy consumption
Authors: Han Song 
Published: February 2021

Abstract
With the continuous development of China’s clean energy industry, the consumption of high proportion of new energy after being connected to the grid has become the focus of attention of the industry. Flexible resources can effectively restrain the fluctuation of new energy generation and improve the stability of power grid. Therefore, in order to fully mobilize the enthusiasm of flexible resources, give full play to the market advantages, guide the market participants of generation side, power consumption side and energy storage side to participate in the Generation Grid Load Storage interaction, this paper establishes a market-oriented energy storage interaction mechanism to promote new energy consumption and form a win-win market system.
Applications of near infrared spectroscopy for fish and fish products quality: a review
Authors: Yu Wenqian 
Published: February 2021

Abstract
Fish and fish products are rich in significant nutrients such as protein and fat, and it is an important part of human diet. However, the deterioration of fish due to the influence of microorganisms and oxidation has not only wasted resources but also affected food safety. Therefore, the development of fast and simple detection technology is an important solution. This paper combines with domestic and foreign literatures, summarizes research papers based on Near-infrared (NIR)spectroscopy, discusses the basic principles, analysis process and modeling methods of NIR spectroscopy respectively, and reviews the application of NIR spectroscopy in physical and chemical indicators, microbial indicators, storage conditions, classification and identification, geographic traceability and other related aspects, which provides a reference for the further development and research of rapid detection technology for fish and fish products.
Based on MOD13Q1 data to analyze the characteristics of vegetation changes in central Yunnan from 2000 to 2019
Authors: Peng Zongqi , Yang Kun , Luo Yi , Yang Jiaying 
Published: February 2021

Abstract
The central Yunnan is an important development area in Yunnan Province. Studying the pattern of vegetation change in this region and the relationship between vegetation change and climate factors can provide information support for the management of the ecological environment and promote sustainable economic development. This study used the meteorological dataset of the Climate Date Store (ECMWF) and the vegetation dataset of MOD13Q1, combined with spatial autocorrelation analysis, simple linear regression analysis and Pearson correlation coefficient analysis to analyze the change of the NDVI and the distribution characteristics of spatial autocorrelation. The results showed that the NDVI value in central Yunnan increased slowly from 2000 to 2019 with the growth rate of 0.027/decade, but the increase was not significant. On the seasonal scale, the growth rate was highest in autumn (0.051/decade). In the past 20 years, the overall Moran I of NDVI was greater than 0.71, and the vegetation in central Yunnan showed a significant positive spatial autocorrelation.
Discussion on the Evolution of Sea Reclamation from 2006 to 2018 in Jimo District, Qingdao, Shandong Province
Authors: Xiu Chun , Lu Xin , Huo Suxia , Li Zhengxu , Ma Tianran , Chen Keke 
Published: February 2021

Abstract
Sea reclamation is an important way to develop marine resources and expand land space. Based on the extraction technology of remote sensing image, the spatial distribution and evolution of sea reclamation in Jimo District from 2006 to 2018 were discussed. From 2006 to 2018, the reclamation area of Jimo District increased by 32.68km2. The industrial structure adjustment, the implementation of major projects and the increase of population were the main driving forces. The reclamation areas are mainly located in Aoshan Bay, Hengmen Bay and Xiaodao Bay, which occupy the former tidal flat and wetland resources of these bays and cause the change of the hydrodynamic environment. At the same time, the problems of land idle and low intensive utilization still remain. In the face of these problems, some measures, such as establishing and improving a long-term monitoring mechanism, reducing the stock of reclamation in accordance with the principles of economization and strengthening the ecological restoration of coastal zones, should be taken.
The Formation of Supermassive Black Holes at Early Universe
Authors: Cao Zhi 
Published: February 2021

Abstract
The high-redshift universe is now the frontier of modern astronomy, and is the key object for current and near-future telescopes. The high-redshift quasars put a tight constraint on existing BH growth model, as it is challenging to form a 1010 M⊙ BH at z∼6.
In this work, we relax the widely-adopted Salpeter BH growth model, to consider a more realistic path. We consider the variation in the mass and angular momentum orientation of gas supply (i.e. through ∊L and n), as well as the change in accretion mode (hot versus cold). Moreover, the conventionally considered BH spin impact on the radiative efficiency ∊M is also taken into account. Our key results can be summarized as follows. Firstly, sufficient gas supply (larger in ∊L) is obviously a key factor to make the BH grow efficiently. Also, The BH spin (a*), through the radiative efficiency ∊M, has a dominant impact on the BH growth, i.e., those high-redshift quasars with MBH > 1010 M⊙ should be formed in a chaotic gas supply situation, where the angular momentum orientation of the gas is random. Finally, through analyzing the most realistic accretion model, we find that the only existing model of seed BH is through the direct collapse, driven by either dynamical processes or thermodynamics