bluuebunny/crossref_metadata_2025 huggingface dataset:
Choristoneura conflictana
. [Distribution map].
Authors: CABI  , EPPO
Published: August 2021

A new distribution map is provided for
Choristoneura conflictana
(Walker) Lepidoptera: Tortricidae Attacks mainly Populus tremuloides, also other Populus spp. and broad-leaved trees. Information is given on the geographical distribution in NORTH AMERICA, Canada, Alberta, British Columbia, Manitoba, New Brunswick, Newfoundland, Ontario, Quebec, Saskatchewan, Yukon, USA, Alaska, Arizona, Arkansas, California, Colorado, Iowa, Kansas, Maine, Michigan, Minnesota, Missouri, Montana, Nebraska, New Mexico, New York, North Dakota, South Dakota, Utah, Wisconsin, Wyoming.
Choristoneura rosaceana
. [Distribution map].
Authors: CABI  , EPPO
Published: August 2021

A new distribution map is provided for
Choristoneura rosaceana
(Harris) Lepidoptera: Tortricidae Polyphagous, but particularly attacks Rosaceae including apple (
Malus pumila
), pear (
Pyrus communis
) and peach (
Prunus persica
). Information is given on the geographical distribution in NORTH AMERICA, Canada, Alberta, British Columbia, New Brunswick, Nova Scotia, Ontario, Quebec, USA, Arizona, Arkansas, California, Colorado, Florida, Georgia, Iowa, Louisiana, Maine, Massachusetts, Michigan, Mississippi, New York, North Dakota, Oregon, Pennsylvania, Texas, Utah, Washington, Wisconsin, Wyoming.
Diabrotica undecimpunctata
. [Distribution map].
Authors: CABI  , EPPO
Published: August 2021

A new distribution map is provided for
Diabrotica undecimpunctata
(Mannerheim) Coleoptera: Chrysomelidae Larvae feed on the roots of maize (
Zea mays
) and other Poaceae; adults attack leaves and fruits of Cucurbitaceae and other crops (soyabean (
Glycine spp.
), Citrus, vegetables). Information is given on the geographical distribution in NORTH AMERICA, Canada, British Columbia, Ontario, Quebec, Mexico, USA, Alabama, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, Ohio, Oklahoma, Oregon, Pennsylvania, South Carolina, South Dakota, Tennessee, Texas, Utah, Virginia, Washington, West Virginia, Wisconsin, Wyoming, CENTRAL AMERICA & CARIBBEAN, Bermuda, El Salvador, Guatemala, Nicaragua.
Anoplophora chinensis
. [Distribution map].
Authors: CABI  , EPPO
Published: August 2021

A new distribution map is provided for
Anoplophora chinensis
(Forster) Coleoptera: Cerambycidae Attacks Citrus and other trees. Information is given on the geographical distribution in ASIA, China, Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hainan, Hebei, Hong Kong, Hubei, Hunan, Jiangsu, Jiangxi, Liaoning, Shaanxi, Sichuan, Xizhang, Yunnan, Zhejiang, Macau, Myanmar, Vietnam, NORTH AMERICA, USA, Georgia, Hawaii.
Ophelimus maskelli
. [Distribution map].
Authors: CABI/EPPO
Published: August 2021

A new distribution map is provided for
Ophelimus maskelli
. Hymenoptera: Eulophidae. Hosts:
Eucalyptus
species, including red gum (
E. camaldulensis
) and Tasmanian blue gum (
E. globulus
). Information is given on the geographical distribution in Europe (Corsica and Mainland France; Greece; Mainland Italy and Sicily, Italy; Mainland Portugal; Balearic Islands and Mainland Spain; and England and Wales, UK), Asia (Israel and Turkey), Africa (Algeria, Morocco and Tunisia) and Oceania (New South Wales, Australia, and New Zealand).
Haplaxius crudus
. [Distribution map].
Authors: CABI  , EPPO
Published: August 2021

A new distribution map is provided for
Haplaxius crudus
(Van Duzee). Hemiptera: Cixiidae. Hosts: coconut (
Cocos nucifera
),
Phoenix
spp. and other Arecaceae. Information is given on the geographical distribution in North America (Mexico, USA, Florida and Texas), Central America and Caribbean (Bahamas, Belize, Cayman Islands, Costa Rica, Cuba, Dominican Republic, Haiti, Honduras, Jamaica, Panama, Puerto Rico and Trinidad and Tobago) and South America (Colombia and Venezuela).
Trirhithrum nigerrimum
. [Distribution map].
Authors: CABI  , EPPO
Published: August 2021

A new distribution map is provided for
Trirhithrum nigerrimum
(Bezzi). Hemiptera: Tephritidae. Hosts: polyphagous. Information is given on the geographical distribution in Africa (Benin, Burundi, Cameroon, Comoros, Congo Democratic Republic, Gabon, Ghana, Kenya, Mali, Mayotte, Mozambique, Niger, Nigeria, Rwanda, Sierra Leone, South Africa, Sudan, Tanzania, Togo and Uganda).
Transits close to the Lagrangian solutions L
1, L
2 in the elliptic restricted three-body problem
Authors: Paez Rocío I , Guzzo Massimiliano
Published: August 2021

In the last decades a peculiar family of solutions of the circular restricted three body problem has been used to explain the temporary captures of small bodies and spacecrafts by a planet of the Solar System. These solutions, which transit close to the Lagrangian points L
1, L
2 of the CRTBP, have been classified using the values of approximate local integrals and of the Jacobi constant. The use for small bodies of the Solar System requires to consider a hierarchical extension of the model, from the CRTBP to the full N planetary problem. The elliptic restricted three body, which is the first natural extension of the CRTBP, represents already a challenge, since global first integrals such as the Jacobi constant are not known for this problem. In this paper we extend the classification of the transits occurring close to the Lagrangian points L
1, L
2 of the ERTBP using a combination of the Floquet theory and Birkhoff normalizations. Provided that certain non-resonance conditions are satisfied, we conjugate the Hamiltonian of the problem to an integrable normal form Hamiltonian with remainder, which is used to define approximate local first integrals and to classify the transits of orbits through a neighbourhood of the Lagrange equilibria according to the values of these integrals. We provide numerical demonstrations for the Earth–Moon ERTBP.
Nonlinear Schrödinger systems with mixed interactions: locally minimal energy vector solutions
Authors: Byeon Jaeyoung , Moon Sang-Hyuck , Wang Zhi-Qiang
Published: August 2021

This paper is concerned with asymptotic behavior of positive solutions for coupled Schrödinger equations with mixed interactions between components. We construct locally minimal energy solutions that show distinctively different limiting profile for simultaneously large attractive and repulsive couplings. The components of the solutions constructed exhibit partial synchronization and segregation.
A numerical stability analysis of mean curvature flow of noncompact hypersurfaces with type-II curvature blowup
Authors: Garfinkle David , Isenberg James , Knopf Dan , Wu Haotian
Published: August 2021

We present a numerical study of the local stability of mean curvature flow (MCF) of rotationally symmetric, complete noncompact hypersurfaces with type-II curvature blowup. Our numerical analysis employs a novel overlap method that constructs ‘numerically global’ (i.e., with spatial domain arbitrarily large but finite) flow solutions with initial data covering analytically distinct regions. Our numerical results show that for certain prescribed families of perturbations, there are two classes of initial data that lead to distinct behaviours under MCF. Firstly, there is a ‘near’ class of initial data which lead to the same singular behaviour as an unperturbed solution; in particular, the curvature at the tip of the hypersurface blows up at a type-II rate no slower than (T − t)−1. Secondly, there is a ‘far’ class of initial data which lead to solutions developing a local type-I nondegenerate neckpinch under MCF. These numerical findings further suggest the existence of a ‘critical’ class of initial data which conjecturally lead to MCF of noncompact hypersurfaces forming local type-II degenerate neckpinches with the highest curvature blowup rate strictly slower than (T − t)−1.
How much has the Sun influenced Northern Hemisphere temperature trends? An ongoing debate
Authors: Connolly Ronan , Soon Willie , Connolly Michael , Baliunas Sallie , Berglund Johan , Butler C. John , Cionco Rodolfo Gustavo , Elias Ana G. , Fedorov Valery M. , Harde Hermann , Henry Gregory W. , Hoyt Douglas V. , Humlum Ole , Legates David R. , Lüning Sebastian , Scafetta Nicola , Solheim Jan-Erik , Szarka László , Loon Harry van , Velasco Herrera Víctor M. , Willson Richard C. , Yan Hong , Zhang Weijia
Published: August 2021

In order to evaluate how much Total Solar Irradiance (TSI) has influenced Northern Hemisphere surface air temperature trends, it is important to have reliable estimates of both quantities. Sixteen different estimates of the changes in TSI since at least the 19th century were compiled from the literature. Half of these estimates are “low variability” and half are “high variability”. Meanwhile, five largely-independent methods for estimating Northern Hemisphere temperature trends were evaluated using: 1) only rural weather stations; 2) all available stations whether urban or rural (the standard approach); 3) only sea surface temperatures; 4) tree-ring widths as temperature proxies; 5) glacier length records as temperature proxies. The standard estimates which use urban as well as rural stations were somewhat anomalous as they implied a much greater warming in recent decades than the other estimates, suggesting that urbanization bias might still be a problem in current global temperature datasets – despite the conclusions of some earlier studies. Nonetheless, all five estimates confirm that it is currently warmer than the late 19th century, i.e., there has been some “global warming” since the 19th century. For each of the five estimates of Northern Hemisphere temperatures, the contribution from direct solar forcing for all sixteen estimates of TSI was evaluated using simple linear least-squares fitting. The role of human activity on recent warming was then calculated by fitting the residuals to the UN IPCC’s recommended “anthropogenic forcings” time series. For all five Northern Hemisphere temperature series, different TSI estimates suggest everything from no role for the Sun in recent decades (implying that recent global warming is mostly human-caused) to most of the recent global warming being due to changes in solar activity (that is, that recent global warming is mostly natural). It appears that previous studies (including the most recent IPCC reports) which had prematurely concluded the former, had done so because they failed to adequately consider all the relevant estimates of TSI and/or to satisfactorily address the uncertainties still associated with Northern Hemisphere temperature trend estimates. Therefore, several recommendations on how the scientific community can more satisfactorily resolve these issues are provided.
Obtaining space-based SDO/AIA solar UV and EUV images from ground-based Hα observations by deep learning
Authors: Liu Tie , Su Ying-Na , Xu Li-Ming , Ji Hai-Sheng
Published: August 2021

In this work, we explore the mappings from solar images taken in Hα (6563 Å) by the Global Oscillation Network Group (GONG) on the ground to those observed in eight different wavelengths (94, 131, 171, 193, 211, 304, 335 and 1600 Å) by SDO/AIA in space. Eight mappings are built by training the conditional Generative Adversarial Networks (cGANs) on datasets with 500 paired images, which are [Hα, AIA94], [Hα, AIA131], [Hα, AIA171], [Hα, AIA193], [Hα, AIA211], [Hα, AIA304], [Hα, AIA335] and [Hα, AIA1600]. We evaluate the eight trained cGANs models on validation and test datasets with 154-pair images and 327-pair images, respectively. The model generated fake AIA images match the corresponding observed AIA images well on large-scale structures such as large active regions and prominences. But the small-scale flare loops and filament threads are difficult to reconstruct. Four quantitative comparisons are carried out on the validation and test datasets to score the mappings. We find that the model-generated images in 304 and 1600 Å match the corresponding observed images best. This exploration suggests that the cGANs are promising methods for mappings between ground-based Hα and space-based EUV/UV images, while some improvements are necessary.
Design and verification of the HXI collimator on the ASO-S mission
Authors: Chen Deng-Yi , Hu Yi-Ming , Ma Tao , Su Yang , Yang Jian-Feng , Wang Jian-Ping , Xu Guang-Zhou , Jiang Xian-Kai , Guo Jian-Hua , Zhang Yong-Qiang , Zhang Yan , Chen Wei , Chang Jin , Zhang Zhe
Published: August 2021

A space-borne hard X-ray collimator, comprising 91 pairs of grids, has been developed for the Hard X-ray Imager (HXI). The HXI is one of the three scientific instruments onboard the first Chinese solar mission: the Advanced Space-based Solar Observatory (ASO-S). The HXI collimator (HXI-C) is a spatial modulation X-ray telescope designed to observe hard X-rays emitted by energetic electrons in solar flares. This paper presents the detailed design of the HXI-C for the qualification model that will be inherited by the flight model. Series tests on the HXI-C qualification model are reported to verify the ability of the HXI-C to survive the launch and to operate normally in on-orbit environments. Furthermore, results of the X-ray beam test for the HXI-C are presented to indirectly identify the working performance of the HXI-C.
Effect of the alidade thermal behavior on the pointing accuracy of a large radio telescope
Authors: Wei Shan-Xiang , Kong De-Qing , Wang Qi-Ming
Published: August 2021

The alidade’s non-uniform temperature field of a large radio telescope is very obvious under solar radiation. Estimating a radio telescope’s pointing errors, caused by the alidade deformation under solar radiation, is significant to improve the telescope’s pointing accuracy. To study the effect of the alidade thermal behavior on the pointing accuracy of a large radio telescope, a temperature experiment is first carried out in a 70-m radio telescope on a sunny day. According to the measured results, the temperature distribution rule of the alidade is summarized initially. In addition, the alidade’s temperature field is calculated by finite element thermal analysis. The simulated results are proved to be in good agreement with the experimental results. Finally, the alidade deformation under solar radiation is computed by finite element thermal-structure coupling analysis. The telescope’s pointing errors caused by alidade deformation are estimated via the alidade’s node displacements. The final results show that the effect of alidade thermal behavior on the telescope’s elevation pointing errors Δ ε
2 + Δ εr
is much more than the effect on the telescope’s cross-elevation pointing errors Δ ε
1. The maximum of Δ ε
2 + Δ εr
is more than 45″, while the maximum of Δ ε
1 is less than 6″. This study can provide valuable references for improving the pointing accuracy of large radio telescopes.
A triplet of the only pulsation mode detected in the DAV star G132–12
Authors: Su Wen-Chao , Fu Jian-Ning , Chen Jian-Xing , Fox-Machado Lester , Zhao Shi-Jie , Ayala-Loera Carmen , Wang Jiang-Tao , Pan Yang
Published: August 2021

Hydrogen atmosphere pulsating white dwarfs, also known as DAV stars, are the most abundant type of pulsating white dwarfs. High-temperature DAV stars in general exhibit a small number of pulsation modes and stable frequencies. G132–12 is one of the pulsating hydrogen atmosphere white dwarf stars which lies close to the blue edge of the instability strip. Previous researches reported that G132–12 might have only one pulsation mode with the period of 212.69 s. To study the pulsation properties of G132–12 in detail, we carried out a bi-site observation campaign in October 2019. Time series photometric data were collected during around 154 h in total. A Fourier analysis reveals three frequencies which are identified as the triplet of an l = 1 g-mode pulsation with the period of 212.499 s. The rotational period is derived as P
rot = 35.0 ± 6.7 h and the inclination of the rotational axis to the line of sight is 70°. G132–12 could be an ideal target for measuring the cooling scale of this white dwarf star with only one excited pulsation mode detected.
Effects of solar radiation pressure on asteroid surface hopping transfers for high area/mass ratio rovers
Authors: Dong Chuan-Jun , Yang Hong-Wei , Li Shuang , Liu Xue-Wen
Published: August 2021

The high area/mass ratio hopping rovers have potential applications in future asteroid surface exploration. This paper systematically investigates the effects of solar radiation pressure (SRP) on ballistic surface hopping transfers for the asteroid 101955 Bennu. Effects of SRP on the traveled distance and the trajectory design of hopping transfers are analyzed and summarized. The simulation results indicate that it is necessary to take SRP into account to ensure the success of hopping transfers and the proper use of SRP can help design the trajectories of hopping transfers with low initial impulses and short transfer times. It also reveals the potential possibility in using SRP to control the post-hopping transfers with specific control policies in the future surface exploration of asteroids.
Correction of the temperature effect in calibration of a solar radio telescope
Authors: Geng Li-Hong , Tan Cheng-Ming , Yan Yi-Hua , Tan Bao-Lin , Liu Dong-Hao , Dun Jin-Ping
Published: August 2021

This work analyzes the annual fluctuation of the observation data of the Mingantu Solar radio Telescope (MST) in S, C and X bands. It is found that the data vary with local air temperature as the logarithmic attenuation of equipment increases with temperature and frequency. A simplified and effective calibration method is proposed, which is used to calibrate the MST data in 2018–2020, while the correction coefficients are calculated from data in 2018–2019. For S, C and X bands, the root mean square errors of one polarization are 2.7, 5.7 and 20 sfu, and the relative errors are 4%, 6% and 8% respectively. The calibration of MUSER and SBRS spectra is also performed. The relative errors of MUSER at 1700 MHz, SBRS at 2800 MHz, 3050 MHz and 3350 MHz are 8%, 8%, 11% and 10% respectively. We found that several factors may affect the calibration accuracy, especially at X-band. The method is expected to work for other radio telescopes with similar design.
A study on universal observation control system and its application for LAMOST
Authors: Wang Zheng , Tian Yuan , Li Jian , Cao Zi-Huang , Zhao Yong-Heng
Published: August 2021

The observatory control system (OCS), a part of automated control of Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST), runs on the CentOS6 platform and implements the communication between modules based on Common Object Request Broker Architecture (CORBA). However, CORBA is complicated and has limited development support; moreover, the official support for CentOS6 has ended. OCS inherently has some shortcomings such as the over-concentration of control and the blocking of device status processing, which hinder the realization of automated observation control of LAMOST. Therefore, this study designs and implements a universal observation control system (UOCS) for optical telescopes. The UOCS takes the device command as the basic execution unit, controls the device execution logic using observation script, controls the observation logic by event-driven messaging, and realizes mutual decoupling between modules via a distributed control mode, thereby ensuring high system robustness. The UOCS performs significantly better than OCS in terms of the observation performance, operator complexity, and communication error. Currently, UOCS is applied to the automated control of some devices and subsystems in LAMOST observation. It will be applied to the automated observation control of Multi-channel Photometric Survey Telescope by 2021.
Analysis and compensation of the reflector antenna pointing error under wind disturbance
Authors: Xu Qian , Zhang Jie , Wang Zhao-Yu , Pan Huan-Zhi
Published: August 2021

A large reflector antenna has been widely used in satellite communications, gravitational wave detection, galaxy origin observation and other fields due to its narrow beam and high gain. With the increase of the antenna aperture and the improvement of the working frequency, the requirements for the pointing accuracy of an antenna are also rising. However, the effect of environmental load on the deformation of the antenna structure, which in turn affects its beam pointing, has become a key problem to be solved urgently in the antenna engineering applications. The key issue to solving this problem involves accurately estimating the pointing error caused by the structural deformation and designing an effective controller that is based on the structural deformation. In this paper, we first establish a dynamic model for antenna structure based on the modal superposition method. The model is then modified by using modal characteristics and the dynamic displacement information of the sampling points to achieve the purpose of accurately estimating the structural deformation. Secondly, by considering the influence of the deformation of the rotating shaft and the reflector surface on the pointing accuracy, a control-oriented pointing error analysis model is established for estimating the pointing error caused by the environmental load in real time. Thirdly, based on considering the influence of the shaft deformation on the error compensation, the feedback error amount is decoupled and corrected to improve the accuracy of the compensation error. Finally, this paper analyzes and verifies the 65 m S/X-band dual reflector antenna with a numerical example. We consider a fluctuating wind with an average wind speed of 10 m s−1 as an example, which results in a maximum pointing error of 55.82″ as calculated by the antenna theoretical model, whereas the maximum pointing error as predicted by our model is 68.27″. The pointing error after compensating for the cause of the environmental load with the modified controller is reduced to 10.57″, which effectively improves the antenna pointing performance.
Stellar dynamical modeling - accuracy of 3D density estimation for edge-on axisymmetric galaxies
Authors: Long Richard J. , Lu Sheng-Dong , Xu Dan-Dan
Published: August 2021

From Rybicki’s analysis using the Fourier slice theorem, mathematically it is possible to reproduce uniquely an edge-on axisymmetric galaxy’s 3D light distribution from its 2D surface brightness. Utilizing galaxies from a cosmological simulation, we examine the ability of Syer and Tremaine’s made-to-measure method and Schwarzschild’s method for stellar dynamical modeling to do so for edge-on oblate axisymmetric galaxies. Overall, we find that the methods do not accurately recover the 3D distributions, with the made-to-measure method producing more accurate estimates than Schwarzschild’s method. Our results have implications broader than just luminosity density, and affect other luminosity-weighted distributions within galaxies, for example, age and metallicity.
High-α-Metal-Rich stars in the LAMOST-MRS survey and its connection with the galactic bulge
Authors: Zhang Hao-Peng , Chen Yu-Qin , Zhao Gang , Zhao Jing-Kun , Liang Xi-Long , Li Hai-Ning , Wu Ya-Qian , Luo Ali , Wang Rui
Published: August 2021

We report the detection of a large sample of high-α-metal-rich stars on the low giant branch with 2.6 < log g < 3.3 dex in the LAMOST-MRS survey. This special group corresponds to an intermediate-age population of 5 – 9 Gyr based on the [Fe/H]-[C/N] diagram and age-[C/N] calibration. A comparison group is selected to have a solar α ratio at super metallicity, which is young and has a narrow age range around 3 Gyr. Both groups have thin-disk like kinematics but the former shows slightly large velocity dispersions. The special group shows a larger extension in a vertical distance toward 1.2 kpc, a second peak at smaller Galactic radius and a larger fraction of super metal rich stars with [Fe/H] > 0.2 than the comparison group. These properties strongly indicate its connection with the outer bar/bulge region at R = 3 – 5 kpc. A tentative interpretation of this special group is that its stars were formed in the X-shaped bar/bulge region, close to its corotation radius, where radial migration is the most intense, and brings them to present locations at 9 kpc and beyond. Low eccentricities and slightly outward radial excursions of its stars are consistent with this scenario. Its kinematics (cold) and chemistry ([α/Fe] ∼ 0.1) further support the formation of the instability-driven X-shaped bar/bulge from the thin disk.
Overview of the results from divertor experiments with attached and detached plasmas at Wendelstein 7-X and their implications for steady-state operation
Authors: Jakubowski M. , Endler M. , Feng Y. , Gao Y. , Killer C. , König R. , Krychowiak M. , Perseo V. , Reimold F. , Schmitz O. , Pedersen T.S. , Brezinsek S. , Dinklage A. , Drewelow P. , Niemann H. , Otte M. , Gruca M. , Hammond K. , Kremeyer T. , Kubkowska M. , Jabłoński S. , Pandey A. , Wurden G. , Zhang D. , Bozhenkov S. , Böckenhoff D. , Dhard C.P. , Baldzuhn J. , Gradic D. , Effenberg F. , Kornejew P. , Lazerson S. , Lore J. , Naujoks D. , Puig Sitjes A , Schlisio G. , Ślęczka M. , Wenzel U. , Winters V. , the W7-X Team
Published: August 2021

Wendelstein 7-X (W7-X), the largest advanced stellarator, is built to demonstrate high power, high performance quasi-continuous operation. Therefore, in the recent campaign, experiments were performed to prepare for long pulse operation, addressing three critical issues: the development of stable detachment, control of the heat and particle exhaust, and the impact of leading edges on plasma performance. The heat and particle exhaust in W7-X is realized with the help of an island divertor, which utilizes large magnetic islands at the plasma boundary. This concept shows very efficient heat flux spreading and favourable scaling with input power. Experiments performed to overload leading edges showed that the island divertor yields good impurity screening. A highlight of the recent campaign was a robust detachment scenario, which allowed reducing power loads even by a factor of ten. At the same time, neutral pressures at the pumping gap entrance yielded the particle removal rate close to the values required for stable density control in steady-state operation.
A study on aluminum metal matrix preforms forging into double-hub flange
Authors: Agrawal M , Singh S
Published: August 2021

The present article presents investigation of deformation characteristics during forging (closed-die) of SiCp AMC. The preform (cylindrical) fabricated via liquid metal stir casting manufacturing route were located centrally in closed-die set with respect to its axis and forged into axi-symmetric double-hub flange component. Initial experiments were conducted to examine the mechanical characterization of the AMC preforms under consideration, which also included investigations into interfacial frictional conditions and stress-strain behaviour of the AMC material. Under a controlled die-travel till the die corners were filled completely, during forging of the preforms, corresponding height reductions and die loads were recorded. The complete deformations were considered in two stages, i.e. free barreling and constrained distortion stages. The theoretical expressions (generalized using ‘Upper Bound’ technique) for strain rates, velocity field, various energy dissipations along with average die loads for all the deformation modes considered in the present study were formulated. The variation in die loads, die cavity fills and energy dissipations due to the effect of preform aspect ratio and die velocity were critically examined and experimentally compared the results.
An Acquaintance to Text-Steganography and its Methods
Authors: Singh A P , Moudgil S , Rani S
Published: August 2021

In this research paper discussion will be going on upon text steganography. As the word ‘steganography’ is very well known amongst human beings, considering that, this research paper will highlight the term ‘Text Steganography’. Defining steganography, that an individual can hide data into/within or behind text, images, audio, and video would not be inappropriate. Digital steganography is a modern approach and necessity of digital security system. Digital Text steganography is a distinct factor of digital steganography. Various types of Text steganography will have been discussed further.
Effect of load on the wear behaviour of Al2O3 HVOF sprayed coating
Authors: Meena SL , Tyagi Ankit , Murtaza Qasim , Walia R.S. , Niranjan MS
Published: August 2021

Al2O3 HVOF sprayed coating has been deposited with controlled process parameters. SEM characterization was used to characterize the deposited coating. Wear, Residual stresses, COF and hardness, are studied at variable load of 40, 50, 60 and 70N. Surface morphology of Al2O3 HVOF coating shows a molten and un-molten powder with curved laminar structure and confirm homogeneous coating. Experimental results revealed that with increase in load wear, hardness, residual stresses, and COF results were enhanced at higher load (70N). Experimental result shows wear value reduces to 80 microns and COF decreased to 0.25, while hardness and residual stresses increased to 470 HV and -20 MPa respectively. The experimental test results reveal that decrease in COF and wear may be occurs oxide layer formation or due to tribo-film formation under increasing load condition
Cloud and mobile computing: the age of virtual internet space
Authors: Singh Dhaneshwar , Madaan Rosy , Panda Supriya P
Published: August 2021

This century is described as Cloud Computing Technology over the Information Technology Business. Cloud computing advancement mostly relies on the Internet possesses the most advanced planning of computation. It records as piles of correlated and schmoozed hardware, software, and internet infrastructure. It blends grid computing and other computing as a community. A short overview of cloud computing is obtained from this research paper by consulting several papers on cloud technologies. The substance conveyed by this represents the perspective of shaping IT businesses and the idea of cloud computing.
A review paper on hypervisor and virtual machine security
Authors: Aalam Zunaid , Kumar Vinod , Gour Surendra
Published: August 2021

A hypervisor is a computer programme or software that facilitates to create and run multiple virtual machines. It is also known as Virtual Machine Manager (VMM). Due to their popularity, it exploits the attack surface, because the Hypervisor code contains much vulnerability. Since the Hypervisor is a core element of any cloud computing service, it is always on the top priority of the attackers. There are many Software (open source) and Hardware-based Solutions are available in the market to monitor and control the hypervisor activities. This paper summarizes various types of attacks, vulnerabilities, security issues and challenges related to hypervisor and virtual machines.
Blockchain Technology, Its Applications and Open Research Challenges
Authors: Kaushal Rajesh Kumar , Kumar Naveen , Panda Surya Narayan
Published: August 2021

Blockchain is a technology that operates on distributed peer-to-peer network and is widely adopted by large number of organizations due to its attractive features such as highly secured, transparent, traceable, low transaction fee, no need of central authority and confidentiality. There are lot of confusions and myths regarding the blockchain technology as it is emerging technology and too complex in nature. This paper is aimed at revealing blockchain technology in depth along with its applications and open research challenges. The past published literature was reviewed to achieve the objectives. The study found that apart from cryptocurrency, blockchain is also suitable for other applications such as smart cities, supply chain, healthcare, smart transportation and authenticating IoT (Internet of Things) devices. This study is also disclosing various open research challenges such as scalability issues, huge power consumption and delay in completing transactions. This paper is also sharing the mitigation approaches and the future of blockchain with smart contracts.
Experimental Analysis of Porter Governor Mechanism in Dynamics of Machinery Laboratory
Authors: Hasan Ali
Published: August 2021

This work is done in the Machine Dynamics Laboratory of Mechanical Engineering Department. All the observations have been recorded using universal governor apparatus set up available in the laboratory. The author studied both the actual as well as theoretical parameters of the porter governor given to the students to perform their experiments. Author noted that, at M= 1, 2 and 3 kg, the actual sensitivity of given porter governor are 24, 11 and 24% respectively. The actual average sensitivity comes to a value of 20%. While with the help of calculations, the theoretical sensitivity of given porter governor are 23, 17 and 8% respectively. The theoretical average sensitivity comes to a value of 16%. Here, it is to be noted that in both the cases, the sensitivity of the studied governor is constant. The research covers both the experimental and numerical approached. The results of this paper may serve a model for researchers in doing research work as per specific necessity in the early stage of their work.
Digital Image Forensic based on Machine Learning approach for Forgery Detection and Localization
Authors: Monika  , Passi Abhiruchi
Published: August 2021

Machine learning for multimedia forensic is a new way of image forgery detection due to its amazing features of fast forgery detection. Compared with existing techniques of Deep Learning and Convolution Neural Network (“CNN”), machine learning improves security in the specific forged region under various test conditions. Some researchers use Support Vector Machine (“SVM”) and k-nearest neighbors (k-NN) algorithms to detect forgeries and another category uses unsupervised classification, including self-organization feature map (SOFM) and fuzzy c-means. But there occurs a need to address the detection speed improvement under the present scenario. The proposed algorithm has been developed using a machine learning approach to improve detection speed by pre-processing of feature extraction and feature reduction using “DWT” and “PCA” where data is trained by support vector machine (“SVM”) to provide quick results under various test conditions. This work specifies different image attacks like all types of geometric transformation, post-processing operations, etc., and presents efficiency in forgery detection and localization in case of multiple forgeries.
Exploration of machine learning methods for prediction and assessment of soil properties for agricultural soil management: a quantitative evaluation
Authors: Motia Sanjay , Reddy SRN
Published: August 2021

Soil is a heterogeneous and complex natural resource that is the factual basis of almost all agriculture production activities. The soil’s inherent nutrients or physiochemical properties help the researchers better understand the soil ecosystem dynamics and play a crucial role in guiding farmland decision-makers in their routine decisions. Therefore, the accurate forecasting of soil leads to improved and better soil health management (SHM). The recent advances in sensing and computational technologies have led to the expanding accessibility of farmland data either obtained distantly or proximally. The increasing availability of massive data and unreservedly accessible open-source algorithms have prompted a quickened use of machine learning (ML) procedures to investigate soil conditions. Therefore, to understand the usage of ML techniques in exploring soil properties and related applications, this paper concentrates on reviewing and analyzing ML techniques precisely to predict and assess soil properties for improved decisions on agricultural SHM. The article also explores various other vital factors like algorithms, implementation tools, and performance metrics employed in numerous soil assessment application domains and different challenges and future research directions for SHM using ML techniques. The detailed assessment concludes that the response for ML in the prediction and evaluation of soil properties for SHM is very promising for the sustainable growth of agriculture.
Performance Evaluation of Novel Convolution Neural Network Architecture for Melanoma Skin Cancer Diagnosis on Different Hardware Processing Units
Authors: Qureshi Mohammad Naved , Umar Mohammad Sarosh
Published: August 2021

Skin cancer is one of the major public health concerns among the white population with more than a hundred thousand cases every year. Melanoma is one of the deadliest forms of skin cancer which is responsible for thousands of deaths in US alone in recent years and, therefore, early diagnosis is very important to increase the survival rate of melanoma patients. In last few years’ Deep neural networks have been utilized by researchers to build best models for classifying or diagnosing skin cancer. In this paper Deep neural network-based CNN architectures to classify Melanoma is proposed. The CNN architecture proposed in this work is implemented on CPU, GPU and TPU and the performance of the model is shown on all these platforms. The proposed model is compared to other works done so far for melanoma diagnosis in terms of various performance metrics like prediction accuracy, specifity, sensitivity and it is observed that the proposed models outperformed them. The dataset utilized in training and testing the proposed models is ISIC archive dataset which contains 4750 skin images for two classes i.e. melanoma and benign. The results of our study have proved that utilizing GPU and TPU speeds up the training 38 times faster than CPU and can accelerate the performance of CNN for features extraction, optimization and classification of skin cancer images and the proposed model has outperformed the other models compared with it.
Potential applications of thermal spray coating for I.C. engine tribology: A Review
Authors: Sonia  , Walia R.S. , Suri N.M. , Chaudhary Sumit , Tyagi Ankit
Published: August 2021

The IC engine has been a conventional source of producing mechanical energy for various applications. The tribopair of piston ring and cylinder liner has to work in adverse tribological conditions such as high temperature, speed and load. The wear of piston ring not only reduce the performance of the tribopair but also cause the failure of the system. The insufficient lubrication at the interface increases the tribological losses drastically. The tribological losses can be minimized by coating of some material which has superior tribological performance. The thermal spray coating can be used for providing a stable coating over the tribological surfaces. The versatile operating conditions and process parameters assist the deposition of required material to a desired thickness over the various substrate materials. The process can be used for producing the stable coating over at a faster deposition rate. The environmental friendly coating material can be used as a bled with the conventional coating material for making the process sustainable.
Multi-Characteristics Optimization in Micro-milling of Ti6Al4V Alloy
Authors: Roushan Ashutosh , Srinivas Rao U. , Patra Karali , Sahoo Priyabrata
Published: August 2021

Nowadays, Ti6Al4V alloy is widely used to fabricate miniaturized prostheses, orthopedic and dental implants. Surface quality is an essential aspect of the implant parts owing to its effect on service life, which could be achieved through a proper selection of precise micromachining parameters. In this research, the mechanical micromachining of Ti6Al4V alloy has been performed, and optimized process parameters are considered for analysis. Surface roughness (Ra) of the machined microchannels, cutting force in the feed direction (Fy), cross-feed direction (Fx), and vibration on the top surface plate along the spindle axis (a z) have been taken as the response variables and were analyzed. The tests were accomplished at various rotational speed (N), feed per tooth (f z), axial depth of cut (a p), and cutter diameter (D) as machining parameters, each at three levels. The significant factors and their levels are identified using analysis of variance (ANOVA) and S/N ratios of response plot. According to the GRA test, N : 15000 rpm, fz : 0.2 µm/tooth, ap : 30 µm, and D : 200 µm are optimal parameters setting for better machinability of Ti6Al4V. ANOVA results indicated that feed rate is the most influential factor for lower cutting forces, surface roughness, and workpiece vibration. Fast Fourier transform (FFT) analysis depicts the stiffness of different micro end-mills significantly affect the machining performance like vibration amplitude during the micro-milling of Ti6Al4V alloy.
Unsupervised Content based Image Retrieval at Different Precision Level by Combining Multiple Features
Authors: Zakariya S. M. , Jamil Mohd Atif
Published: August 2021

Image retrieval is a procedure of finding appropriate images in the image database. There are two types of image retrieval systems in common practice. These are the text-based image retrieval (TBIR) system and content-based image retrieval (CBIR) system. The content based system is proven to be more effective in which the visual contents of the images are extracted and described by multi-dimensional feature vectors. In this work, several models are developed by combining different image features in a combination of two and three. To begin with, three different models based on the combination of two features, viz., color with shape, shape with texture, and color with texture are designed. A three features based model is considered with color, shape, and texture in the next step. The retrieval rate of the mentioned models is assessed in terms of precisions. The results are obtained using COREL standard database. This study shows that the images can be better retrieved using three features based model in contrast to models using two features.
Performance Analysis of Complex Manufacturing System using Petri Nets Modeling Method
Authors: Kumar Amit , Kumar Vinod , Modgil Vikas , Kumar Ajay , Sharma Anita
Published: August 2021

The Petri nets modeling method is a powerful tool for the performance analysis of industrial systems. The main factor which makes it more effective among the various popular simulation methods is the ability to deal with the real working conditions. The data obtained from such a manufacturing system is generally full of uncertainties and the Petri nets modeling method deals with this data to reflect the real behavioral pattern of different sub-systems installed in the plant. The Petri nets-based simulation method provides the availability of the sub-systems for a long time period by running the plant in virtual manners. The results obtained through the analysis can be utilized to identify those sub-systems which highly affect the system availability and separate maintenance planning for each sub-system can reduce the production loss due to unavailability of any sub-system for performing its intended task. The proposed methodology has been demonstrated in this paper using a complex repairable manufacturing system.
A Multi-Objective Approach for Software Quality Improvement
Authors: Makkar Priyanka , Sikka Sunil , Malhotra Anshu
Published: August 2021

Software industry always demands high-quality software that must be reliable, robust, flexible, reusable, effective, and extendable. To improve software quality refactoring is an efficient and frequently opted technique. Most of the refactoring work has been done on the source code level less work has been done on model-based. Model base refactoring is more difficult to estimate. In this research paper, the multi-objective evolutionary algorithm based on decomposition (MOEA/D) is applied to find how software quality is affected by refactoring technique. It impacts the software quality in both positive as well as negative way.
Comparison of Fly Ash Based (AAC) Block and Clay Bricks for Structure and Strength Properties
Authors: Singh V , Behl V , Dahiya V
Published: August 2021

Fly Ash, a waste product collected from precipitators of coal based thermal power plants can be utilized as a potential resource as construction material. Fly ash, being fine light weight silica particles can cause environmental pollution if not managed properly, and/or not utilized as construction material. Fly ash can be used along with cement, cementitious materials to develop bricks and blocks which possess good properties for civil engineering structures. This paper presents comparative analysis of clay bricks and fly ash based autoclaved aerated concrete (AAC) block properties, methodology, process and material required for preparing fly ash based AAC block as per Indian standard code provisions, inspection and quality control. The textures of the blocks with fly ash were very similar to that of clay bricks; the sample with the additive contains spherical fly ash particles. These fly ash particles led to reduction in the density of the blocks and a substantial improvement in their durability. Use of this additive could have practical implications as a means of recycling and for achieving cost savings in blocks production. The structural cost, cement mortar for plaster & masonry, breakage, construction speed, quality, fitting & chasing, carpet area, availability, energy saving, chemical composition of fly ash based AAC blocks compared with normal clay bricks that delivered good results. From the present study, it can be concluded that fly ash based AAC blocks can be used as an alternative to clay bricks because of their strength, uniformity and smooth surfaces and lower cost. The cost of fly ash-based blocks was found about 20-35 % lesser than the clay bricks.
Internet of Things (IoT) based Smart Helmet for Construction
Authors: Kuhar Preeti , Sharma Kaushal , Hooda Yaman , Verma Neeraj Kumar
Published: August 2021

In India, the use of helmets is mandatory at construction sites as per the government rules. The Use of a helmet protects the labor head against the impact of the falling object from any height. There was a modification in the ordinary helmet into a smart helmet by adding the Work Mode (ON/OFF) system, GPS System, Smoke Sensor, Task Completion Button. In this, the helmets will automatically be updating the work mode ON, if someone wears it because a clamp turns the system ON and information goes to the supervisor. Same as this, there are two more buttons which indicate the task completion and about the emergency. Using all these buttons and GPS Systems helps the labor in many ways and manage the tasks and time also. For this, GPS and an IOT System are being used for the functioning of a helmet. Real-time signals will be sending constantly with the help of installed various sensors to monitor. The main objective of this study is to activate the installed components so that the various emergencies can be detected at the supervisor’s room or to find the location of the worker, to keep an eye on the various field tasks. It will give the actual location of the worker and in case of emergency; the labor can send his/her exact location to the command office of the construction site. For this, HC12 technology is chosen to give the information by sending pinpoint location, HC12 module which has a GPS module. These components are installed in the ordinary helmet and connect all these with a single computer so that all the activities are to be supervised in a single computer. By installing all the components in one construction helmet, the internet of things based smart helmet is assembled.