bluuebunny/crossref_metadata_2025_split huggingface dataset:
Methods of mathematical statistics application in assessing the density of actual and forecasting distribution density of residual oil reserves
Authors: Gabdrahmanova K F , Izmailova G R , Samigullina L Z 
Published: July 2020

Abstract
The authors propose a method for mathematical statistics application for residual reserves in deposits predicting. They propose a method for making residual the current reserves distribution model based on geological and physical characteristics of the reservoir analysis. The article takes the first step to justify the use of statistical methods in the conditions of operational facilities of the Romashkino and Tuymazy oil fields. One of the urgent problems associated with the effective oil fields development is not only a reliable estimate of the distribution density of residual reserves, but their forecast for the subsequent development as well. There are many ways to estimate residual reserves nowadays. All of them are, to one degree or another, based on residual oil saturation ratio estimating, which in the conditions of insufficient accuracy of geophysical methods, as well as their rise in price (carbon-oxygen logging, for example) or their limited application, calls for other approaches in the residual oil reserves value assessing, based, for example, on the field data. Logging methods have their limitations. Their application requires other approaches in residual reserves amount assessing. Having analyzed multiple studies results, such as, for example, field data, implemented in the SPSS program regression analysis, which allows statistical data the processing the authors propose the mathematical statistics methods application in assessing the density of the actual and forecasting the residual oil reserves’ distribution density. The mathematical modeling results for oil from a porous medium displacement process are presented for Romashkino and Tuymazy oil deposits.
Study of efficiency of methods for determining fatigue limits through the example of its determination for welded joints of marine stationary platforms
Authors: Starokon I V 
Published: July 2020

Abstract
Currently, the world is actively engaged in the extraction of oil, gas and other useful resources at offshore fields using offshore stationary platforms. Due to the fact that the platforms are operated for a long time, fatigue damage accumulates in them. This issue becomes especially important when assessing the residual life of welded joints of the offshore platform, the repair of which is carried out using various technologies. The resource of such compounds is determined on the basis of the fatigue diagram, the key value of which is the fatigue limit. A large number of theories have been developed to determine the fatigue limit. However, calculations based on these theories do not always give a correct estimate. Therefore, the purpose of this article is to study the effectiveness of various methods for determining endurance limits using welded joints of offshore stationary platforms as an example and to select a method that allows obtaining the most accurate value of fatigue limit.
Monitoring of technological processes and assessment of technical condition of pumping units
Authors: Galeev A S , Bikbulatova G I , Boltneva Y A , Sabanov S L 
Published: July 2020

Abstract
Remote monitoring of pumping equipment operation in real mode is being widely introduced at oil and gas industry enterprises. The controllers applied in this process enable preventing progressive destruction of equipment and emergency failures and implementing automatic control of machines’ operation. The actual data collected by these controllers is transferred to the company’s servers and makes it possible to effectively set and address various tasks on equipment maintenance. However, there is still insufficient number of applications to address the problems of pumping equipment operation. The presented paper is aimed at resource efficient operation of equipment by obtaining the information on both actual and predicted technical state of the equipment in real-time mode. The main performance characteristics of a pump deteriorate in the process of its operation, followed by an increase in specific power consumption for injection (with the reservoir properties unchanged). Economic losses due to pump’s wear and tear are determined by the price of electricity and the cost of overhauling. Implementation of the designed monitoring system will make it possible to automatically decide whether further operation of the pump is unprofitable and if it needs to be overhauled. Based on the analysis of the trend of monthly unit costs, the pumping unit will be timely removed for major overhaul when the trend reaches its minimum, which shall provide an average annual economic benefit up to 4,000,000 rubles per pumping unit.
Separation of analytical signal for atomic-emission microwave plasma measurements
Authors: Drokov V V , Vl Drokov V , Kazmirov A D , Sinitskaya A V , Ivanov N A , Hodunaev A Y 
Published: July 2020

Abstract
The analytical signal for atomic-emission microwave plasma (AEMP) spectral analysis method is studied. It is shown that the signal consists of two parts: background signal, proportional to content of the analytical element in a sample shaped by submicron particles and metalorganic compounds; pulse signal, proportional to content of analytical element in coarse discrete particles. The “dynamic discrimination” algorithm is suggested that allows measuring the element content in a liquid or powder ore sample independently of the content shape using AEMP method. It is shown that atomic absorption (AA) and AEMP measurements of Fe, Cu agree within error for samples both low and high in content of element in submicron particles.
Elimination of aperiodic components of measuring elements of relay protection
Authors: Buryanina N S , Korolyuk Y F , Koryakina M L , Lesnykh E V , Suslov K V 
Published: July 2020

Abstract
The authors propose the algorithms to calculate the actual values of currents and their derivatives. The algorithms allow a sharp reduction in the aperiodic components of currents in the calculated actual values and their derivatives. The algorithms are developed to calculate the instantaneous values of positive- and negative-sequence currents when the information obtained during a time interval equal to two milliseconds or less is used. An algorithm is devised to calculate the sinusoidal components of the currents in the presence of aperiodic components in the samples. To eliminate the disoperation of digital relay protection and improve the accuracy of fault location, it is necessary to eliminate the influence of aperiodic components in the currents drawn to the measuring devices of relay protection. The algorithm completely eliminates the aperiodic component at any time constants and is implemented by four samples of currents. The four samples of currents separated by three sampling intervals are sufficient for calculating all the parameters of currents, including the positive and negative-sequence currents, in particular in the case when the magnetic cores of current transformers reach saturation. The proposed methods for setting the industrial frequency parameters to avoid the aperiodic components in short-circuit currents are based on the algorithms that process the data from three and four samples of currents.
Estimation of efficiency of the thermal method in the development of gas-hydrate deposits
Authors: Davletshina M R , Chiglintseva A S , Stolpovskii M V 
Published: July 2020

Abstract
In the work on the basis of the proposed mathematical model, the process of decomposition of methane hydrate under thermal action on the reservoir is numerically investigated. Based on the calculations, it was shown that the energy efficiency of the decomposition of methane hydrate, i.e. the ratio of the energy obtained by burning the released methane to the energy spent on heating the formation decreases with increasing temperature of the coolant. The formation temperature distributions are also presented and the dependences of the position of the phase transition boundary on the system parameters are investigated. The problem is solved in a plane-one-dimensional formulation. According to the proposed scheme, a homogeneous porous layer of finite length, containing methane hydrate in the initial state, is considered. In this problem, we believe that the decomposition of hydrate into water and gas occurs at the boundary of phase transitions.
Potential Analysis of Majapahit Fruit Powder (Crescentia cujete L) as Shrimp Immunostimulants using the in Silico Method
Authors: Rahmaningsih Sri , Andriani Riska 
Published: July 2020

Abstract
Shrimp production is currently constrained by many diseases. These diseases are conventionally prevented by administering chemicals as immunostimulants, with their attendant side effects. Alternative natural ingredients as immunostimulants in shrimp production are being sought, and Majapahit plant (Crescentia cuje L.) is one. In vitro and in silico studies on the plant’s stems, leaves and fruits showed the plant’s desirable effects on the immune system of Vannamei Shrimp, as the plant contains important bioactive compounds (e.g. carotenoids, phenolics, alkaloids, pectin, tannins, flavonoids and terpenoids). The present study determined the ability of Majapahit fruit powder mixed into shrimp feeds in enhancing the immune system of the seafood. Liquid chromatography–mass spectrometry (LC-MS) revealed quercetin flavonoids as the effective active ingredient in the powder, which in silico study proved to be an effective immunostimulant for shrimps.
Improving biodiesel properties by mixing jatropha oil and soybean oil
Authors: Wahyudi W , Nadjib M , Pahlevi D M , Rohman B S N 
Published: July 2020

Abstract
The need for biodiesel as an alternative fuel will increase along with the increasing energy consumptions and the depletion of fossil fuel reserves. Jatropha oil and soybean oil are potential raw materials for biodiesel. Each raw material gives different properties to biodiesel. Mixing the two types of oil makes it possible to improve the quality of biodiesel. The aim of this study was to determine the effect of variations in the composition of the oil mixture on the biodiesel properties. Jatropha oil was mixed with soybean oil in various compositions. The mixture was heated and stirred for 60 min at 90°C. The more the percentage of soybean oil biodiesel, the viscosity of the biodiesel mixture decreased. Mixing with 20% soybean oil has a significant reduction in viscosity. The increasing percentage of soybean oil also influences the higher heating value of the biodiesel mixture.
Classification Using C4.5 Algorithm in Election Participation Prediction
Authors: Fitrani Arif Senja , Rosid Mochamad Alfan , Taurusta Cindy , Fauzia Indah 
Published: July 2020

Abstract
The General Election of the President, DPD, DPR, Provincial DPRD and Regency / City DPRD in 2019, in Indonesia, is carried out by an independent institution namely the General Election Commission (KPU), where there is a measure of the success of the holding by holding the principle of direct, general, free of secrecy. Another component of the election will be the implementation of contestants and voters. In the electoral factor, this is also a measure for success in the overall implementation process, which is a success if the participation of the community is high in the holding of elections. And conversely, if the community participation is low, one of them is the level of public trust in the organizer (government) decreases. Analysis of classification mining data with C4.5 algorithm places the prediction class “Present” and “Not Present” on the permanent voter list (DPT) taken from form C7 (voter attendance list form). C7 data was obtained from polling stations (TPS) located in the village of Wonokasian, Wonoayu District, Sidoarjo Regency, East Java. The number of datasets is 4249 instances, and the number of attributes is 10. With split datasets, for training data are 2965 instances, and testing data are 1284 instances. From testing, the testing data obtained the results of true or appropriate accuracy of 1151 instances (90%) and obtained incorrect or incompatible data as many as 134 instances (10%). This shows a good value for the results of 90% of the corresponding data in the prediction class in the Presidential Election, DPD, DPR, Provincial DPRD, and Regency / City DPRD in 2019.
Application of a combination between Principal Component Analysis and Logistic Regression Based on Support Vector Machine on Educational Data Mining with Overlapping Data Problem
Authors: Mutrofin Siti , Maisarah Maisarah , Widodo Slamet , Ginardi Raden Venantius Hari , Fatichah Chastine 
Published: July 2020

Abstract
In 2019, the government of the Republic of Indonesia issued a zoning-based policy for New Student Admissions (PPDB) from the level of elementary school (SD) to high school (SMA), especially for public schools. The policy is documented in Permendikbud No.51 / 2018. The government policy aims to ensure the equality of education and make prospective students not focus only on favorite schools. However, this policy raises new problems. One of them is that if the potential student has got a medium UN (National Examination) score or medium distance of the house to the destination school, then his potential to be accepted at the destination school is very small. It is even worse if the potential students do not know the lowest score and the farthest distance the destination school can accept. Thus, potential students will choose schools by only guessing without basing on valid data, so their chances of being accepted will be very small. This current research focused on Educational Data Mining at PPDB Public High School (SMA) in Jombang in the academic year 2019/2020 which aims to accommodate the needs of potential students to predict the destination schools based on their own grades and home distances using classification techniques of data mining. However, another problem emerged in this study. An overlapping data occurred where one data was also owned by more than one class. For example, a potential student of SMA Negeri 2 Jombang (SMAN 2 Jombang) has got a score of 80 in Bahasa Indonesia subject, which is the same as that of a student from SMA Negeri 3 Jombang (SMAN 3 Jombang). Data overlapping does not only occur in one data but almost all of the data. The data used in this study were 600 data, consisting of 308 from PPDB 2019 of SMAN 2 Jombang, and the rest were from SMAN 3 Jombang. The attributes used were the home distance from the destination school, overall UN scores, UN scores of Mathematics, Natural Sciences, Bahasa Indonesia, and English subjects. The algorithm used was a combination of Principal Component Analysis (PCA) with Logistic Regression (LR)-based Support Vector Machine (SVM) with Anova kernel. The validation applied 10-fold cross-validation and the evaluation of algorithm performance used the aspects of accuracy, precision, and recall. The results of this current study showed an accuracy of 94.33%, a precision of 96.28%, and a recall of 92.53%. The results were better than those that did not apply PCA (70.83% accuracy, 69.62% precision, and 76.62% recall). By PCA, data could be seen from another angle that could separate or differentiate one class from the others. Even though there were 100% overlapping data, none of them, from all attributes, was 100% exactly the same.
Smart campus attempt using green transportation mobile-based tracking app
Authors: Rachmaniah M , Suroso AI , Syukur M , Hermadi I , Putra RW , Tirani MRG 
Published: July 2020

Abstract
Green campus is the creation of a green ecologically friendly environment that leads to smart campus establishment. In this study, green campus status is revealed by applying cross-campus community collaboration under green transportation bus. The purpose of this study was to develop a real-time Android-based tracking system, using the V model approach, aimed at green transportation movements and accessibility. The global positioning system of green transportation is interconnected via a back-end server that utilizing web-socket to incorporate client and server communications. The results are passenger app that enabling the passenger to track green transportation movement, acquire green transportation meta-information, perceive campus routes, and send awaiting notification. Further results are driver app for green transportation drivers to choose which vehicle to drive, change driving status, recognize other active coaches, locate nearer passengers stops, and identify campus routes. The created mobile app has successfully experimented on Android smartphones such as Samsung Galaxy Mega J5, Lenovo A6000, Xiaomi Redmi 3, Asus 2 Zenfone Laser, and Samsung J7 Prime.
Evaluation of PHP Framework Measured Using Object-Oriented Metrics with the Analytic Hierarchy Process
Authors: Setiyawan R , Gata W , Elbiansyah  , Ardiansyah D , Yuliandari D , Wijayanti D , Harmono F P , Komalasari Y , Lase M , Fakhriza M H 
Published: July 2020

Abstract
The existence of various PHP frameworks may become one alternative choice in developing a web application that PT XYZ wants to evaluate its Wisanggeni internal PHP framework in order to measure how far the design quality of Wisanggeni framework is working. An evaluation on PHP framework using object-oriented metric parameter and design quality is then conducted in this research. The results of measurement conducted using object-oriented metric parameters for each framework are evaluated with the Analytic Hierarchy Process (AHP) method to determine the best framework model design quality used as a reference for the development of Wisanggeni. This study also uses a combination of PHPDepend and PHPMetrics devices to measure the values of object-oriented metrics in each PHP framework. The research final result is that each framework has one value representing each framework’s quality in which the quality of Wisanggeni framework is almost to the same with the Laravel and CodeIgniter framework.
Numerical Studies on Fast Pyrolysis of Palm Kernel Shell in a Fluidized Bed Reactor
Authors: Thoharudin  , Chen Yi-Shun , Hsiau Shu-San 
Published: July 2020

Abstract
Numerical studies using Computational Fluid Dynamics (CFD) of thermal decomposition of Palm Kernel Shell (PKS) have been conducted in a fluidized bed reactor under atmospheric pressure of nitrogen as fluidization gas. To investigate the effect of temperature, the fast pyrolysis temperature was varied in a range from 400 °C to 650 °C. Furthermore, the effect of PKS feeding rate was also studied in a range from 300 g/h to 1500 g/h combined with variations of nitrogen superficial velocities. It was found that the increase of temperature results in the greatening of conversion efficiency and non-condensable gas product yield. The maximum 60.5 % liquid/tar product yield was obtained in 500 °C. The increase of PKS feeding rate led to the reduction of conversion efficiency due to the thermal energy shortage for the decomposition process. However, the increase of PKS feeding rate could reduce the non-condensable gas product with the insignificant change in liquid product yield. The rising superficial velocity of nitrogen favoured the shorter residence time resulting in the increasing tar product yield.
Frequency selection for ground monitoring using propagation characteristics
Authors: Suherman  , Hanafiah Ali , Mubarakah Naemah , Wijayanto Erwin 
Published: July 2020

Abstract
Ground monitoring can be used for observing ground structure changes or other specific objectives. Rather than using expensive ground penetration radar, the ground propagation characteristics may be able to describe the structure changes. Ground propagation can be evaluated by using a simple radio transmitter and receiver. This paper employs a vector network analyzer (VNA) to explore ground propagation characteristics. As the available VNA works from 500 MHz to 1 Ghz, the paper proposes how to select suitable frequency for ground monitoring. Tangential comparison between mathematical model and direct measurement is proposed. The result shows that the selected frequency exerts promising propagation characteristic even dough signal diffraction causes irregular signal strength at the receiver.
The influence of extrusion temperature on the structures and mechanical properties of Mg–Al–4Y alloys
Authors: Wang Jinhui , Yuan Xiaoguang , Jin Peipeng , Zhu Yunpeng , Li Mingyue 
Published: July 2020

Abstract
In this study, Mg–Al–4Y alloys were successfully prepared via the melting and casting method. The alloys were then extruded at 450 °C, 500 °C, and 550 °C. The influence of the extrusion temperature on the microstructures and mechanical properties of the alloys was investigated. The results indicated that the Al2Y phase was coarse and agglomerated in the Mg matrix. A strong {0001} basal fiber texture was formed in the alloys extruded at 450 °C; meanwhile, the alloy grains were refined, and the Al2Y phase was distributed uniformly in the matrix; these combined occurrences dramatically enhanced the strength and hardness of the alloys. As the extrusion temperature was increased from 450 °C to 550 °C, the yield strength, tensile strength, and hardness of the alloys gradually decreased, but the elasticity significantly increased. The yield strength reduced from 209.6 MPa to 197.8 MPa, the tensile strength reduced from 311.5 MPa to 271.1 MPa, and the hardness reduced from 77.5 HB to 62.2 HB, while the ductility increased from 2.9% to 15.0%. Based on the experimental results, the high strength and hardness of the alloys were mainly due to fine grain strengthening, second phase strengthening, and {0001} basal fiber texture strengthening.
The evolution of flowering phenology: an example from the wind-pollinated African Restionaceae
Authors: Linder H Peter 
Published: July 2020

Abstract

Background and Aims
Flowering phenology is arguably the most striking angiosperm phenophase. Although the response of species to climate change and the environmental correlates of the communities have received much attention, the interspecific evolution of flowering phenology has hardly been investigated. I explored this in the wind-pollinated dioecious Restionaceae (restios) of the hyperdiverse Cape flora, to disentangle the effects of phylogeny, traits, and biotic and abiotic environments on flowering time shifts.

Methods
I recorded the flowering times of 347 of the 351 species, mapped these over a 98 % complete phylogeny and inferred the evolutionary pattern and abiotic correlates of flowering time shifts. The patterns and biotic/abiotic correlates of restio community mean flowering time were explored using 934 plots.

Key Results
Restios flower throughout the year, with large spring and smaller autumn peaks. Species flowering time is evolutionarily labile, poorly explained by either the environment or traits of the species, with half of all sister species allochronic. Community mean flowering time is related to elevation, temperature and rainfall.

Conclusions
Flowering time shifts may result from assortative mating and allochronic speciation, possibly leading to non-adaptive radiation. However, community mean flowering time may be environmentally selected. Diversification of flowering time may be non-adaptive, but species could be filtered through survival in suitable communities.