bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radiosonde studies of internal waves in the southern near-equatorial atmosphere of the Earth
Authors: Gubenko VN , Kirillovich I A , Andreev V E 
Published: August 2021

Abstract
Radiosonde measurement data of the wind speed, conducted on 28 February and on 15 November 2007, have been used for the internal gravity waves (IGWs) identification and determination of their parameters in the Earth’s lower stratosphere over Cocos Islands (coordinates: latitude –12.04°S and longitude –96.90°E). A wind speed hodograph analysis has shown that observed fluctuations are wave-induced while the wave energy propagates upwards. Using the results of a wind speed hodograph analysis, dispersion equation and polarization relations, we have obtained the magnitudes of key IGW characteristics such as the intrinsic frequency, amplitudes of vertical and horizontal perturbations of the wind speed, vertical and horizontal wavelengths, intrinsic vertical and horizontal phase (and group) speeds, wave kinetic, potential and total energy. An original method for determining the wave ground-based frequency and azimuthal angle of IGW propagation in the Earth’s atmosphere has been proposed. Application of the developed method to radiosonde measurements, conducted on 28 February 2007, has given a possibility to establish that the wave ground-based frequency is equal to 14.0· 10−4 rad/s and it corresponds to the actual wave period T=1.25 hours.
Investigations of the Atmospheric Moisture Contents Variations Using Ground-Based Microwave Radiometers
Authors: Karavaev D M , Shchukin G G 
Published: August 2021

AbstractThe method of microwave radiometry for investigations of the atmospheric water vapor and integrated cloud liquid water content is considered. Some results of experimental studies of temporal and spatial variations in the integrated water vapor and cloud liquid water contents using ground-based microwave radiometers during different meteorological condition as well as during developments of dangerous weather phenomena are presented. The results of the experiments confirm the prospects of using microwave radiometric information for forecasting of dangerous weather events associated with the development of convective clouds and thunderstorms.
Effects of radiation of quantum-structural elements of clouds in remote sensing of the atmosphere Effects of radiation of quantum-structural elements of clouds in remote sensing of the atmosphere
Authors: Ganzha A A , Kuznetsov I E 
Published: August 2021

AbstractThe article shows that clouds and their elements are formed in the atmosphere in the form of large ensembles of quantum-structural (QS) clusters, which are able to radically change the radiation characteristics of the Earth’s atmosphere and other planets. The unique abilities of large ensembles to form fluxes of high-energy particles, antiparticles, and gamma rays (dark lightning) in the atmosphere are explained. Theoretical studies are supported by the results of field and laboratory experiments with quantum-structural filaments (QSF).
Capacities of TEC measurements by the low-cost GNSS receiver based on the u-blox ZED-F9P for ionospheric research
Authors: Kogogin D A , Nasyrov I A , Sokolov A V , Shindin A V , Ryabov A V , Maksimov D S , Zagretdinov R V 
Published: August 2021

Abstract
A prototype of a low-cost GNSS receiver assembled on base of the u-blox ZED-F9P module is described in the paper. The original low-cost GNSS receiver (OGNSS-R) allows made the parallel registration of 184 channels in the entire frequency range (1176 ÷ 1610 MHz) of the main GNSS (GPS, GLONASS, Galileo, Beidou) and recording raw data of carrier-phase, pseudorange (code) and signal strength measurements. The obtained data processing allows to calculate the slant total electron content (TEC), TEC variations and other most popular TEC-based indices of ionospheric activity. The comparative studies of these parameters and similar parameters obtained by simultaneous measurements on the professional geodetic GNSS receiver Trimble Alloy (KZN2 station of the IGS network) were preformed. The analysis showed the median value of the signal strength at the L1 frequency for the KZN2 station are 8% higher than that at the low-cost GNSS receiver based on the u-blox ZED-F9P module (KZN2–48.75 dBHz; OGNSS-R – 45dBHz). For the L2 frequency that difference is less than 2% (KZN2–49.4 dBHz; OGNSS-R – 48.5 dBHz). The median levels of relative slant TEC and TEC-based indexes of the ionospheric activity obtained by the Trimble Alloy receiver at KZN2 station are 25÷50% lower than for the u-blox ZED-F9P receiver. Thus, the using of starter kits such as the simpleRTK2b debug board based on the u-blox ZED-F9P module described in the paper, is really actual for creating a permanent network of GNSS-stations and/or for carrying out field measurements in experimental campaigns.
The Tangential Velocity Estimation Algorithm for Space-borne SAR
Authors: Khramov K K , Tolstov E F , Kostrov V V 
Published: August 2021

Abstract
This article presents a discussion of one of the important areas of application of synthetic aperture radars (SAR) – the moving target indication (MTI) mode. The principle of trajectory signal processing in MTI systems is based on the estimation of the Doppler frequency or phase shift of the echo signals due to the movement of objects. The paper describes an algorithm for estimating the tangential velocity of moving targets for the MTI system based on the use two apertures displaced along trajectory of SAR spacecraft. The structure of the MTI system based on the analysis of phase and amplitude radar images is considered. Further, the amplitude and phase characteristics of the moving target are obtained. The block diagram of the tangential velocity estimation algorithm is given. Simulation has been performed and the features of the operation of this algorithm are presented. The errors in estimating of the target tangential velocity are determined.
Mathematical models of noise characteristics of high-speed digital-to-analog converters of radar signal generators
Authors: Romashov V V , Romashova L V , Doktorov A N , Yakimenko K A , Sochneva N A 
Published: August 2021

Abstract
A mathematical model of the power spectral density of phase noise of high-speed digital-to-analog converters in one side frequency band of tuning is obtained. Calculated using the developed mathematical model of the power spectral density of phase noise of high-speed digital-to-analog converters from Analog Devices in the efficiency mode in the NRZ baseband showed a small error in comparison with the experimental characteristics. It is shown that in the 2 × NRZ oversampling mode, the phase noise level of the high-speed DAC is 7-8 dBc/Hz lower than in the main NRZ operation mode.
High-resolution experimental dual-wavelength remote sensing synthesized aperture radar: technical appearance and flight test results
Authors: Rovkin M E , Ermakov R V , Samuleev M S , Djakov I V , Yu Dostovalov M 
Published: August 2021

Abstract
A model of new high-resolution two-wavelength aviation synthesized aperture radar (SAR) for remote sensing of the Earth, technical appearance of the system and indicators achieved are presented in the article. The technique and results of conducted flight tests of the SAR prototype as well as examples of obtained radar images are given in the work. The achieved new SAR performance at spatial resolution was equal 0.21 m and 0.5 m in X-and L-band respectively with a viewing bandwidth at a maximum resolution of 8.4 km. In the light of the development of the use of UAVs in Russia, it is concluded that the creation of a compact version of high-resolution SAR with a reduced flight ceiling and maximum range is relevant.
Analysis of the directional pattern of a non-equidistant antenna array with a random arrangement of radiating elements in three-dimensional space
Authors: Tersin V V , Bulkin V V 
Published: August 2021

Abstract
A three-dimensional antenna array with a spherical surface was investigated. The channels were randomly placed at array points with a vertical and horizontal step equal to 0.45 wavelengths. For uniform filling of the sphere, the minimum allowable distance between the channels was introduced, depending on the number of channels and the sphere size. The maximum side lobe level depends on the number of channels. To calculate the path difference in a given direction, the coordinate system was rotated so that one of the coordinate axes coincided with the selected direction. To find the radiation pattern, the scalar product of the amplitude-phase distribution vector corresponding to the signal emission direction was calculated by the complex-conjugate vector of the amplitude-phase distribution corresponding to all possible directions of signal arrival from an external source.
Erratum: Embedded system for ultrasonic imaging of under-water concrete structures
Authors: Jain H. , Patankar V.H. 
Published: August 2021

Abstract
Many of the modern concrete structures such as sea-links and bridges are built in water. They require structural health monitoring (SHM) and audit to ascertain the quality and estimation of remaining useful life. To meet these requirements, a single-channel ultrasonic imaging system has been designed and developed to detect defects, porosities and rebar locations inside the Concrete/ Reinforced Cement Concrete (RCC) structures. This real-time and reconfigurable embedded system was evaluated by carrying out under-water imaging of Concrete and RCC test blocks. Conventionally, Ultrasonic Pulse Velocity (UPV) method is being utilized over three decades in Transmit-Receive (T-R) mode to estimate the density and strength of the concrete structure under test. UPV method requires a skill to interpret the data provided by the UPV instrument. The novelty of the single-channel system discussed in this paper is that it is capable of inspecting Concrete/ RCC structures both in Pulse Echo (PE) as well as in T-R mode. An application software has been developed using C# in a visual environment for image acquisition and the control of Data Acquisition (DAQ) hardware has been interfaced to the computer via USB. The imaging system performs data acquisition and coherent averaging of the RF bipolar data to achieve Signal-to-Noise Ratio (SNR) higher than 20 dB. The performance of the system was evaluated by acquiring B-Scan images of the water submerged concrete test blocks having Side Drilled Hole (SDH) and RCC blocks with one as well as two steel rebars, using 54 kHz water immersion transducer in PE mode. The acquired B-Scan images have revealed the internal details of the sample test blocks, resembling the defects generated in the test blocks. High voltage tone burst bipolar pulser with maximum output of (±350 V) has been specifically designed for this system to inspect highly attenuative porous and non-homogeneous Concrete/ RCC materials for the detection of SDH and reinforced steel bars in the concrete test blocks, using B-Scan imaging technique.
The Sensitivity of Maximum Magnitude Range Parameter in Bedrock Acceleration Calculation for 2500 Years of Return Period, Case Study: Bengkulu Province, Indonesia
Authors: Azwar C M , Syahbana A J , Sari A M , Irsyam M , Pamumpuni A , Sadisun I A 
Published: August 2021

Abstract
Infrastructure development such as multi-storey buildings, toll roads, bridges, housing, and others continue to be carried out to improve the economic region. Those things require planning and a good foundation in order to have a durable and earthquake-resistant building. Earthquake is one of the most destructive geological hazards and can trigger other geological hazards, such as landslides, tsunamis, liquefaction, and land subsidence. Bengkulu Province, Indonesia, is one of the susceptible areas to this hazard. The earthquake hazard assessment is important to do to reduce the risk of material and immaterial loss. This study aims to determine the sensitivity of the maximum magnitude range parameter using the probabilistic seismic hazard analysis (PSHA) method using USGS PSHA software. The result obtained from this study were in Bengkulu Province with all earthquake sources show the value of bedrock acceleration with 2500 years of return period in the range 1.2 – 1.5g. The observed sensitivity shows that Bengkulu Province has a sensitivity value in range of 0.01 – 0.03 with the highest value being in Bengkulu City with a value (0.02722) due to uncertainties of maximum magnitude with range of (+0.1) Mw and the fault source indicates that Lebong has a value of (0,05890742).
The Critical Path Method in Construction Project Rescheduling
Authors: Zakia  , Febrianti Dian 
Published: August 2021

Abstract
Generally, Projects have a deadline, which means the completion of the project must be on time because the successful implementation of a project is an important goal for both the project owner. Management involvement is required for executing the project more effectively and efficiently from the beginning of the task, project completion time and cost. The program needed to project scheduling, project completion time and cost. The problem discussed in this study is the CPM calculation result using Microsoft Project, how to identify the critical path and float in each activity with the CPM. The purpose is to obtain the results of time scheduling calculations using Microsoft project-based CPM, to analyze the critical path of the CPM, and to find out activities that have a grace period. Based on shop drawing, SNI analysis is carried out which is the starter to make project schedules with duration calculated from SNI analysis. The calculation result and data input carried out in Microsoft Project create 180 workdays with 22 activities are on a critical trajectory which takes 20,635 hours. After the authors reschedule the project implementation lasted 172 working days, there were 7 activities on the critical trajectory, spending 18,339 hours.
Effect of GGBFS on Compressive Strength, Porosity, and Absorption in Mortars
Authors: Sambowo K A , Ramadhan M A , Igirisa F 
Published: August 2021

Abstract
This research aims to determine the influence of Granulated Blast Furnace Slag (GGBFS) as an ingredient partially added cement in the making of mortar against compressive strength, porosity, and absorption of mortar. This method of research uses experimental methods. The Mortar mixture used is 1 PC: 2 PS and 0.5 cement factor. GGBFS variations are used at 0%, 10%, 20%, 30%, 40%, and 50% of the weight of cement. This research used cubes with a size 5 cm × 5 cm × 5 cm with a sample amount of 36 pieces with a test age of 7 days. The research results gained compressive strength mortar than mortar control, but at a percentage of 30%, GGBFS bagasse ash in a portion of cement has decreased in strength. Compressive strength at the age of 7 days obtained 10.93 MPa; 11.73 MPa; 17.33 MPa; 10.8 MPa; 16.27 MPa, and 16.8 MPa. The compressive strength the maximum average found in the variation of 20% and a variation of 20% GGBFS is a variation that meets the Type M Mortar plan’s compressive strength of 17.2 MPa.
Behavior of Curved Double Steel-Concrete Composite Shear Walls Under Cyclic Loading
Authors: Çobanoğlu Ö , Guo Q 
Published: August 2021

Abstract
In this study, effects of different curved structures on mechanical behavior of curved double steel-concrete composite shear (SC) walls under cyclic loading were investigated numerically. Firstly, the experimental results of a straight SC wall under cyclic loading were used to validate numerical result. After then, curved SC walls were designed in ABAQUS according to different radius-thickness (R/t) ratios (5,10,15,20,25,30,40). In numerical studies, in-plane monotonic response, cycling response, and out-of-plane monotonic response were investigated by changing the loading. The results showed that among all parameters, the R/t ratio:5 has better seismic performance by 11.87% than straight SC wall under cyclic loading. In addition, it was found that when the ratio of the radius of curvature to the section thickness values were greater than 10, curved SC walls behaved as straight SC walls. When the R/t ratio was bigger than 10, the ultimate load and damage of wall load dropped consistently. According to in-plane monotonic response results, R/t ratio:5 has a 13.6% better peak force than straight wall when it is compared with other R/t ratio values. Calculated results showed that although there is no effect in bearing capacity when R/t ≥ 10, it increased by 35.4% when R/t is 5.
Prediction Models of Infrastructure Resilience as a Decision Support System Based on Bayesian Network
Authors: Agustin A D , Adi T J W 
Published: August 2021

AbstractThe impact of climate change is the implication of global warming that affects people around the world, including Indonesia, which is causing more the intensity and type of natural disaster that causes a decrease or malfunction of a city. To reduce the impact of climate change is needed for the application of the concept of resilience. Resilience is the ability to withstand disturbances caused by external factors and the ability to recover if damage occurs. One of the natural disasters is an earthquake is a natural disaster that often occurs in Indonesia and generally causes significant damage to the physical condition of buildings and infrastructure. This study aims to create a prediction model to measure the impact of a disaster as a decision support system such as a mitigation strategy and responses to identify measures that can improve performance infrastructure to meet resilience goals. One of probabilistic methods is the Bayesian Network method. It is a graphical model probabilistic that represents a set of variables and freedom probabilistic usingconditional-probability-table. This research expects as a proposed method of assessing resilience infrastructure to cities in Indonesia when natural disasters occur, especially earthquakes.
The New Analysis of Discrete Element Method Using ARM Processor
Authors: Ma’arif F , Gao Z , Li F , Ghifarsyam H U 
Published: August 2021

Abstract
The discrete element method (DEM) is widely used to predict the motion over time of many particles, such as molecules or soil particles. The computational demands for DEM simulations are significant. Therefore, improved performance could address a spectrum of scientific and engineering applications. This paper proposes an accelerated implementation for the DEM using Advanced of Reduced Instruction Set Computing Machine. The method used in this research is to compare the results of the ARM versus x86 analysis. The case study refers to the investigation conducted by V. Ćmilauer using YADE programming. The results showed that the performance of ARM as a microprocessor was capable of DEM analysis. Furthermore, because the arm stands alone as a system, it runs both Ubuntu and Windows operating systems without affecting each other’s performance and capabilities. Finally, the study will focus on ARM processing as future works.
The Study of Bond Strength of Reinforced Concrete Structures on Severe Environment
Authors: Pramudiyanto  , Widodo S , Sumiyanto J 
Published: August 2021

Abstract
Reinforced concrete is a composite material made up of two components with unequal mechanical behaviour and physical features. This action is produced by the interaction between both of its components, plain concrete and reinforcing bars. In, general, the external load is applied to concrete and to the reinforcing bars receive its part of the load only from the surrounding concrete by bond. So, bond stress is the shear stress acting parallel to an embedded bar on the surface between the bar and the concrete. The aim of this research is to investigate the behaviour of concrete characteristic on severe environment, and the bond strength of steel reinforcement with two different treatments. The concrete compressive strength is taken to be 35 MPa, as recommended on standards. The test commenced are compressive test and bond strength test. The concrete compressive strength, (f’c
) have met the criteria, since the average compressive strength obtained from the test are above 35 MPa. The concrete quality control has a poor-quality control, which has coefficient of variation 10.99% against ACI 214R-11 requirement. The bond strength using painted reinforcement shows the relatively good performance rather than using waterproofed concrete and the bond strength using waterproofed concrete shows relatively flat performance. With the point of view of practical aspect, the waterproofed concrete seems to be more practical rather than painted reinforcement.
The Influence of Rattan Fibre Addition to The Compressive Strength of Normal Concrete
Authors: Yusra A , Salena I Y , Sari D P , Asrianur A 
Published: August 2021

Abstract
Concrete is high in compressive strength but low in tensile strength and very brittle material. In this study, rattan fibre used as an added material to help eliminate the brittle properties of normal concrete. Variations of fibre used consisted of 0%, 0.5%, 1%, 1.5%, and 2% by weight of cement with mixed planning using the American Concrete Institute method. The compressive strength and stress-strain tests were carried out when the concrete was 28 days old, with a design compressive strength of 25 MPa as many as 15 pieces. The value resulting from testing on normal concrete without the addition of fibres is 24.94 MPa, 0.5% variation of rattan fibres is 23.23 MPa, 1% variation of rattan fibre is 25.3 MPa, 1.5% variation of rattan fibre is 25.85 MPa, 2% variation of rattan fibre is 23.59 MPa. Normal concrete compressive strength test showed an increase in strength at 1.5% rattan fibre and decreased at an additional 2%. The result of stress-strain test in normal concrete without rattan fibre is 0.00125, 0.5% of 0.00254, 1% of 0.00067, 1.5% of 0.00053, 2% of 0.00333. The stress-strain test shows that the addition of rattan fibre can help eliminate the brittle properties that are lacking in normal concrete in general.
Assessment of Ground Movement at Cigombong Bridge by Using Finite Element Analysis: A Case Study in West Java, Indonesia
Authors: Arafianto A , Rahardjo P P 
Published: August 2021

Abstract
Ground movement phenomena were detected at abutment A2 of Cigombong Bridge, causing the abutment to hit a girder. A thorough investigation has been performed by inspecting the structure condition and nearby landslide occurrences directly on site. Additional borings with Standard Penetration Test (SPT) were also conducted to evaluate the actual soil condition in the abutment area. Moreover, monitoring of subsurface movement was performed regularly with inclinometers. Such additional borings and inclinometers were located at the road elevation beside the wing wall and the existing ground surface near the abutment footing. During the installation of inclinometer pipes, soil identification and SPT were conducted. Consequently, the soil condition and SPT N-value profiles can be obtained. It was established that the original soil condition is very soft clay with an SPT N-value of 1 to 4 blows/30 cm. Furthermore, the inclinometer monitoring results showed that lateral displacements were identified in both inclinometers. Based on these findings, a 3D finite element analysis was then performed to investigate the effects of ground movement on the abutment and the foundations. The results showed a possibility of pile crack and overstressed pile due to the ground movement induced by compression of soft soil.