bluuebunny/crossref_metadata_2025_split huggingface dataset:
The resilience of buildings to climate change: the role of mobile passive systems
Authors: Roca-Musach M. , Alonso-Montolio C. , Cabillo I. Crespo , Coch H. 
Published: December 2023

Abstract
Climate change indicates that we are heading towards higher temperatures worldwide and greater temperature variations. To face this challenge, we need to adapt to coming conditions and minimize negative impacts on people and the environment. In this paper, we aim to generate evidence to inform decision-making when designing buildings in Switzerland by considering possible future climatic conditions and maximizing the time when buildings do not require neither heating nor cooling systems. We compare two cases, a static scenario where passive systems are permanent (wall and roof thermal insulation), and an adaptable scenario that accounts for movable passive systems (interior shutters, cross ventilation, and solar protection). The results show that the adaptable scenario returns over 1000 hours of free-running conditions more than the static case, both for 2050 and 2070. In the static scenario, the free-running period represents 25% of the year, while in the adaptable scenario it represents around 40%. Thus, passive strategies with movable devices can be a suitable approach to adapt buildings to future climate conditions, which would provide larger periods of free-running conditions, lower energy demand, and lower costs on permanent thermal insulation.
Unbalancing mean radiant temperature and air temperature
Authors: Meggers F M , Yazici B , Kim J , Chen K , Merchant C , Izuhara I 
Published: December 2023

Abstract
Radiant heating and cooling systems promise to provide heat transfer over large surface areas to enable lower temperature supply improving both supply efficiency and user comfort. Radiant panels provide both radiant and convective heat transfer. We investigate the balance of the heat transfer occurring via radiation and convection. A commonly referenced benefit of radiant panels is that the radiant heating or cooling delivered to occupants allows thermal perception to remain neutral while lowering or raising air temperatures, which in turn reduces heat losses or gains through the facade. In our previous work on radiant systems, we have observed that very rarely do air temperatures actually get set to more ideal temperatures alongside the radiant panels. Using the framework of a recent study of an office space in Singapore we present a simulation showing the breakdown of radiant and convective heat and the resulting air temperature in a simple heat balance model. We then use a computational fluid dynamics (CFD) model and analytical model to observe the relationship between air temperature and mean radiant temperature (MRT) through space. We find that it can take up to 40 kW of additional heat gain to successfully decouple the air temperature from the MRT generated by the panel by more than 2 °C. We also show that in the CFD model, while the air temperature and MRT remain relatively tightly coupled, the vertical spatial variation of MRT is significant, changing by more than 2 °C across the space from floor to ceiling.
Assessment of drag prediction techniques based on radar data for supersonic vehicles
Authors: Doso M , Khali M , Zakaria M Y , Ahmed M Y 
Published: December 2023

Abstract
Flight testing is probably the most accurate approach for defining the aerodynamic characteristics of a flying vehicle. This is justified by the fact that compared to other approaches, either engineering or computational ones, flight testing is indeed the one that perfectly resembles the real flight environment. Flight data are either obtained by measuring the vehicle’s kinematics via onboard sensors or by tracking the vehicle’s flight via (commonly) radars. The advantages of the latter approach are evident in cases where modifying the vehicle design is not possible or in cases where rival/enemy vehicles are examined. The key issue for this approach is the quality and demands of the technique by which vehicle aerodynamic characteristics are reduced from flight-tracked data. In the open literature, different techniques are used to analyze radar data of vehicle position and utilize them to predict vehicle drag coefficient. Each technique has its strengths and pitfalls. In this paper, the three well-used techniques of drag estimation from radar data namely, Least Square (LS), Maximum Likelihood Estimation (MLE), and Stepwise regression (SR), are considered. The underlying principle, the output, and the range of validity for each technique are addressed with emphasis on what differentiates each of them. The viability and validity of the three techniques are addressed based on the own flight testing of a free-flight supersonic vehicle and using the point-mass flight model. Meteorological data are also recorded and flight conditions are used to enhance the resulting calculations. Based on experimental data available from the literature, a comparison is conducted for the techniques examined. Considering the lack of flight data utilized, and in conjunction with data from the literature, it has been concluded that the SR technique outperforms for a higher sample rate, however, the MLE is more feasible when there is a lack of data.
Position control of Stewart platform with electric linear actuator
Authors: Mohamed M R , Roshdy A A , Ali A A , Fayed M A 
Published: December 2023

AbstractIn recent decades, several technological applications have depended on manipulators like Stewart platform due to its accuracy and precision. Based on actuation type, Stewart platforms could be rotary or linearly actuated. Electric linear actuators are devices commonly consist of DC or AC motors coupled with lead screw or mechanism of gears and spindle which are used to convert rotary motion into linear (push or pull) motion. To increase accuracy and precision and achieve the desired linear actuator response, controllers should be used. The main aspiration of this work is to investigate the feasibility of using PID controllers for position control of Stewart platform with linear actuators. The mathematical model has been derived and the model transfer function has been obtained. To meet the required response of performance characteristics, the PID controller has been designed based on analysis of root-locus. Model simulation analysis has been carried out on both MATLAB and Simulink. For the electric linear actuator, comparison between the obtained response and the results of Ziegler-Nichols tuning method has been discussed on basis of the specifications of the time response. The PID controller parameters for the electric linear actuator has been tested experimentally and compared with simulation results.
Modeling and analysis of nonlinear backstepping controller for the crazyflie quadrotor trajectory tracking
Authors: Zekry O H , Ashry M M , Hafez A T , Attia T 
Published: December 2023

Abstract
This paper illustrates the Newton-Euler laws-based nonlinear dynamic model of a Crazyflie Quadrotor Unmanned Aerial Vehicle (CF-QUAV). It demonstrates the state-space-form equations that govern how the CF-QUAV moves around its frame (body). A Proposed nonlinear control strategy is used to regulate the height (z), position (x, y), attitude (roll and pitch), and heading (yaw) angles. This strategy is based on a Backstepping nonlinear controller defined by Lyapunov theory. The proposed controller can replace the Proportional-Integration-Derivative (PID) controller utilized in the CF-QUAV model to follow the desired trajectories gleaned from CF lab tests. In addition, the parameters of the proposed controller are tuned using the Genetic Algorithm (GA) in order to achieve the best performance and stability of the CF-QUAV model. Simulation-based experiments with statistical analysis are carried out to evaluate the performance of the proposed nonlinear controller and compare its performance and stability with the linear PID controller.
Small RCS targets detection based on pulse compression radar signal generator and processor
Authors: Zahra A G , Youssef A , Talha M , Ahmed F M , Mehany W 
Published: December 2023

Abstract
In the last two decades, field programmable gate arrays (FPGAs) have become the leading technology for implementing real time systems, specially radars. The most important advantage of FPGA is its parallel nature of executing complicated algorithms. As a result, the received data flow will be processed in a real time manner, which is suitable for radar applications. This paper attempts to show the design and the FPGA implementation of a binary phase-coded pulse compression radar signal generator and processor, that are intended to determine the ranges, and the speeds of targets with small radar cross-section area like drones. The system operating waveform is a bi-phase sequence, that is known to have the best known peak sidelobe level compared to compound Barker codes of the same length. In addition, the design incorporates a range sidelobes cancellation method to remove the time sidelobes in the matched filter output. Also, we are going to represent and investigate the FPGA implementing steps of the radar waveform generator and processor according to the required parameters. Finally, the implementation results of the proposed system will be represented.
Modelling of grid-following current-controlled VSC
Authors: Saad E , Helmy S , Elkoteshy Y , Abouzayed U 
Published: December 2023

Abstract
The voltage sourced converter (VSC) is a basic element in the grid connected solar-PV system that used in converting the DC-generated power from the solar-PV to AC power compatible with the utility grid. In this paper, a grid connected, three phase, two level VSC model and its control technique are simulated. The switched model of a three phase, two level VSC with active and reactive power controller is employed. The VSC’s control is performed based on the grid following VSC methodology. In order to control the transferred active and reactive power between the VSC and the grid, a current control mode (CCM) in dq0 frame is used and discussed in the following sections. The mathematical models of all elements of control loops are developed. Furthermore, the design of these control components is presented with their performance curves using PSCAD/EMTDC software.
CRB-based comparative study of array signal processing direction finding methods supported with SDR platform implementation
Authors: Elkasrawi O A , Abdelaziz A M , AbouBakr H E , Aboelazm M A 
Published: December 2023

Abstract
Radio Direction-Finding (DF) is an extremely important process in numerous commercial and military applications. Array signal processing-based DF methods have been developed to improve estimation performance in recent applications that require higher resolution and accuracy. Practically, angle of arrival (AOA) estimation is challenging due to various intrinsic and extrinsic parameters that affect the results. Therefore, clarifying these parameters and researching their impact on various DF methods are considered important research topics. The Cramer-Rao Bound (CRB) for estimating AOA is calculated based on a model of a linear antenna array system. This bound identify the factors that significantly impact the estimation performance. The current study conducts a comparative analysis of the most widely used array-signal-processing-based direction-finding (DF) methods under different conditions of the CRB parameters. According to the simulation results, Multiple Signal Classification (MUSIC) AOA estimator provides more accurate and stable results. Accordingly, it is chosen for implementation using a prototype testbed based on Software Defined Radio (SDR) technology using National Instruments Universal Software Radio Peripheral (NI-USRP) platform version 2930. Experimental outcomes were tested at various AOA values. The appendix includes the complete derivation for the CRB relation applied on the system model.
Low-complexity joint transmit diversity and adaptive modulation schemes for OGS-satellite FSO uplink
Authors: Elsaidy E , Rakia T , Abdelaziz M , Abd El-azeem M H 
Published: December 2023

Abstract
In this paper, we present two novel low-complexity transmission schemes for optical ground station (OGS)-satellite free space optical (FSO) uplink. Specifically, the TCAM-scheme which is a joint dual-branch threshold combining and adaptive modulation scheme and the SCAM-scheme which is a joint dual-branch selection combining and adaptive modulation scheme. In both schemes, the data rate is adjusted according to the instantaneous received combined SNRs at the satellite. We analyze the performance of the proposed schemes in terms of the outage probability, the average spectral efficiency and average bit error rate, while considering both subcarrirer intensity modulation/direct detection (SIM/DD) and coherent FSO detection techniques. Numerical results show that both TCAM and SCAM schemes provide better performance as compared to a single FSO uplink, while SCAM scheme enjoys better performance than TCAM scheme. This comes at the expense of increased complexity of the SCAM scheme. Also, coherent FSO detection technique shows better performance than the SIM/DD FSO detection technique for both schemes. The choice of which scheme and which FSO detection technique to use is a compromise of required quality of service and complexity.
Optimizing SIFT algorithm parameters for better matching UAV and satellite images
Authors: Elorabi K A , Zekry A , Mohamed WA 
Published: December 2023

Abstract
Image registration has been increasingly employed in various applications such as target identification, 3D mapping, and motion tracking. The main idea of Image registration is aligning two or more images of the same scene captured from different viewpoints, at different times. Scale-invariant feature transform, SIFT, is considered one of the most robust algorithms used in image registration for extracting and matching features under different conditions. Using SIFT algorithm default parameters in Matching UAV and satellite Images provides unreliable results due to the nature of aerial images because the dynamic range is quite low. The number of extracted features depends on the image content and the selected parameters. In this paper we tuned SIFT parameters to get the best performance with aerial images, to increase the number of features (SM) and the correct match rate (CMR) which increases the efficiency of the process of registration. The algorithm is validated by matching a large number of aerial images taken by mini-UAV with satellite images for the same region.
Experimental investigation of a hybrid steel truss reinforced concrete beam for aerospace shelters
Authors: Lofty E A , Kamal I M , Hassan M A , Hassan K M 
Published: December 2023

Abstract
This paper illustrates experimentally the significance of using hybrid steel truss reinforced concrete beam (HSTRCB) in the construction of aerospace shelters. A finite element analysis was carried out in a previous stage to compare the flexural behaviour of HSTRCB with steel truss beams (without concrete casting) and traditional reinforced concrete beams. The Finite element simulations showed a significant improvement in the flexural behaviour of the HSTRCB. In this paper two beams were tested by 4-point bending test. The first is standard reinforced concrete beam. The other is HSTRCB with steel angles as top and bottom reinforcement. Stirrups were replaced by vertical steel plates. Flexural behaviour was represented by the load-deflection curves. Results showed that the adhesion strength between steel truss members and concrete should be enhanced. Failure occurred due to slippage between steel truss elements and concrete. Moreover, HSTRCB showed a noticeable improvement in the ductile behaviour for the zone after the ultimate capacity.
3D Printed Proto Type Model of Pelton Turbine Runner
Authors: Shah H A , Chaudhari G C , Dhiman V D 
Published: December 2023

Abstract
Nowadays, different methods are used in the renewable energy sector for the fabrication of prime movers. A broad classification of the latest additive manufacturing technologies is discussed with ten different parameters like material used, speed, part size, accuracy, application, surface finish, complexity, costing, strength and weakness. Additive manufacturing or 3D printing is also referred to as digital manufacturing technology. 3D printing technology creates physical objects from a geometrical representation by successive addition of materials. Polylactic acid material will be cost-effective to develop the laboratory scale prototype Pelton turbine model. The fused deposition method gives durable products with plastic filament material. FDM provides an optimum condition for the manufacturing of curved surfaces. A step by step process is emphasis for the digital printing of 3D Pelton buckets, runner and shaft. Difficulties associated with the orientation of the Pelton bucket is overcome by using mechanical support structures.
Numerical Analysis of Traditional and Hooped Pelton Runner at Various Operating Conditions
Authors: Karna Aaditya , Chitrakar Sailesh , Bhurtel Mausam , Baral Bivek , Solemslie Bjørn W 
Published: December 2023

Abstract
Pelton turbine is an impulse turbine that converts kinetic energy of incoming jet of water into mechanical energy. Due to impingement of high-speed jet on buckets, Pelton turbine experience high stress at the tip of bucket and at the connection of bucket and rim. To provide the structural strength to the runner, a hoop is attached to it which allows better distribution of forces. However, the impact of hoop on the hydraulic performance of runner is important to assess. For this, a numerical analysis based on Computational Fluid Dynamics has been performed on both traditional and hooped Pelton runner. Transient analysis has been done to calculate the efficiency of both runners under same boundary conditions. The analysis was performed at different openings of needle. Numerical study showed that the efficiency of hooped Pelton runner is less compared to traditional Pelton runner at higher and medium openings. However, at lower openings hooped runner is more efficient. The efficiency drop was in the range of 3.56% to 1.25%. Flow contours reveal that obstruction of fluid is more prominent at higher opening than lower openings, which is the main reason for efficiency drop. Hoop, despite giving structural strength to the runner, is detrimental to the hydraulic performance of traditional runner.
Design and numerical study of a pump-turbine for retrofitting of an existing francis turbine
Authors: Pokharel Nischal , Thapa Biraj Singh , Solemslie Bjørn Winther , Thapa Bhola 
Published: December 2023

Abstract
Energy is the vital requirements of daily life. It is mainly concerned with production, storage, balance and distribution. Hydropower is a key sources of renewable energy. Regarding the storage of hydropower energy, pumped storage comes in the foremost choice. The runner is the main component of pump storage hydropower project. As the energy storage trend is shifting for pump storage hydropower project, the design methodology and operating range of reversible pump turbine play major role. The pump turbine has always compromise in efficiency due to the same machine operating in both turbine and pump mode. Similarly flow instability in the major hurdles in pump turbine. The initial cost for the pumped storage hydropower will certainly be high. Due to this, research trend has been now shifted in possibility of retrofitting of existing hydropower with pumped storage. This is also the true for the study presented here, where the retrofitting of reversible pump turbine in existing hydropower project. The basic dimension for the reversible pump turbine is taken from the existing model Francis Turbine. The blade profile has been changed by increasing blade passage area. Numerical analysis has been performed in both pump mode and turbine mode by at different guide vane angles. Finally the results are discussed with future recommendations.
Seismic Assessment of Underground Structures in the Weak Himalayan Rock Mass for Hydropower Development
Authors: Thapa Umesh Jung , Karki Sujan , Khadka Shyam Sundar 
Published: December 2023

Abstract
This study focuses on the seismic assessment of underground structures in the transition of Higher Himalayan and Lesser Himalayan region of Nepal. Due to fragile geology of the Himalaya, most of the underground structures are constructed in the highly jointed rock mass. Rock mass classification approaches are extensively used for the estimation of supports without seismic consideration. Design of the underground structures like tunnels and cavern seismic effect is rarely considered in the Nepal Himalaya. For the sustainable development of hydropower project tunnel and caverns plays vital role in terms of its stability. Presence of faults, and crushed zone, along the alignment of tunnel, the existing in-situ stress increases beyond its critical level and strength. The long-term seismic behaviour of an underground structure is very essential in weak rock mass. A detailed dynamic analysis of underground response is evaluated using 2D numerical analysis with the geological data, rock mass and fault encountered in hydropower tunnel, through case study. A comparison is then made between the analysis result of the tunnel response with and without seismic consideration.
Influence of Tunnel Shape on the Shotcrete Lining Stress
Authors: Bajgain Sudip , Khadka Shyam Sundar , Khatri Prawal Keshar , Thapa Umesh Jung 
Published: December 2023

Abstract
Tunnel excavation is generally done using drill and blast method and the weak geology causes the over breaks of tunnel. The over breaks not only increases the cost and construction time but also it has influence on the stress on shotcrete lining. This paper presents the influence of shape of the tunnel on the shotcrete lining stress is studied using a numerical modelling with the case study of Kathmandu University Research Tunnel. The region of over breaks is taken as 0.15-0.30 m for weak rock mass [1].Two numerical models have been prepared and the obtain result shows that the stress on the shotcrete lining increases with increase in the over breaks and should be consider in the design of shotcrete lining if the shotcrete lining is to be used as final lining.
Analysis of the Correlation between Genetic Traits and Pathogenic Sites Based on Multiple Linear Regression Model
Authors: Zhou Junjie , Yu Haiping , Yang Liu 
Published: December 2023

Abstract
Current research shows that many phenotypic traits, susceptibility to diseases, and drugs of the human body are related to some pathogenic sites. Locating the position of loci associated with traits or diseases in chromosomes or genes helps researchers understand disease traits and genetic mechanisms and prevent the occurrence of certain genetic diseases. Select 1000 data sets of two types of sample (disease and health) information, including disease information of the sample, 9445 site coding information and gene information of these sites. Two types of methods are used to analyze the correlation between the pathogenic sites and related traits, the chi-square test method is used to find the sites with the highest probability of pathogenicity between single disease and pathogenic sites, and the multiple regression analysis model is used to determine the most likely pathogenic sites between multiple phenotypic traits and sites. Use statistical tools and software to solve the model, and use the error detection rate (FDR) method to conduct multiple comparisons and corrections for each regression parameter. The conclusion of the modeling analysis is consistent with the standard conclusion provided by the 17th Organizing Committee for Mathematical Modeling of Postgraduates. This shows that the comprehensive method of chi-square test and multiple linear regression modeling is reliable, and has universal and reference significance for finding the pathogenic sites of a certain genetic disease and locating the pathogenic genes.