This paper aims to define the concept of time and justify its properties within the universal context, shedding new light on the nature of time. By employing the concept of the extrinsic universe, the paper explains t...This paper aims to define the concept of time and justify its properties within the universal context, shedding new light on the nature of time. By employing the concept of the extrinsic universe, the paper explains the observable universe as the three-dimensional surface of a four-dimensional 3-sphere (hypersphere), expanding at the speed of light. This expansion process gives rise to what we perceive as time and its associated aspects, providing a novel interpretation of time as a geometric property emerging from the dynamics of the universe’s expansion. The work offers insights into how this extrinsic perspective can address phenomena such as the universe’s accelerated expansion and dark matter, aligning the model with current observational data.展开更多
During the past few decades, it has become clear that the distribution, sizes, and masses of cosmic structures are best described as fractal rather than homogeneous. This means that an entirely different formalism is ...During the past few decades, it has become clear that the distribution, sizes, and masses of cosmic structures are best described as fractal rather than homogeneous. This means that an entirely different formalism is needed to replace the standard perturbation model of structure formation. Recently, we have been developing a model of cosmology that accounts for a large number of the observed properties of the universe. A key component of this model is that fractal structures that later regulated the creation of both matter and radiation came into existence during the initial Planck-era inflation. Initially, the vacuum was the only existence and since time, distance, and energy were uncertain, its only property, the curvature (or energy), was most likely distributed randomly. Everything that happened after the Planck era can be described by the known laws of physics so the remaining fundamental problem is to discover how such a random beginning could organize itself into the hierarchy of highly non-random self-similar structures on all length scales that are necessary to explain the existence of all cosmic structures. In this paper, we present a variation of the standard sandpile model that points to a solution. Incidental to our review of the distributions of cosmic structures, we discovered that the apparent transition from a fractal to a homogeneous distribution of structures at a distance of about 150 Mpc is a consequence of the finite size of the universe rather than a change in the underlying statistics of the distributions.展开更多
Dispersion measure in an FRB’s signal is produced by the photons of the radio waves interacting with the free electrons in the IGM. In New Tired Light (NTL), redshifts are produced by the photons of light interacting...Dispersion measure in an FRB’s signal is produced by the photons of the radio waves interacting with the free electrons in the IGM. In New Tired Light (NTL), redshifts are produced by the photons of light interacting with these self-same electrons and so, one would expect a direct relationship between the DM of an FRB and the redshift of the host galaxy. However, workers in this field assume expansion and weight the DM by dividing it by the scale factor (1 + z) to allow for expansion. Once this weighting is removed, it was predicted back in 2016 (when the first FRB was localized) and later presented at a conference and published in the proceedings that, as more FRB’s were localized, a graph of DM versus ln(1 + z) would be a straight line of gradient (mec/2hre) or 7.32 × 1025 m−2 in SI units. The original paper had twenty-four data points but this has risen significantly to sixty-four useable FRB’s and so this corrigendum updates that paper so that all sixty-four are used. The data give a straight-line graph of gradient 7.12 × 1025 m−2, a difference of 3% from (mec/2hre) predicted nine years earlier.展开更多
In July,the Ali CMB Polariza〓〓tion Telescope(AliCPT)of〓〓ficially released high-quality maps of 150 GHz radiation from the Moon and Jupiter.The quality of these images not only validates the exceptional performance...In July,the Ali CMB Polariza〓〓tion Telescope(AliCPT)of〓〓ficially released high-quality maps of 150 GHz radiation from the Moon and Jupiter.The quality of these images not only validates the exceptional performance of the core instrument of AliCPT-1 but also signifies the successful completion of its first-stage con〓〓struction.展开更多
A team of researchers from the Beijing Normal University,the Institute of High Energy Physics(IHEP)under the Chinese Academy of Sciences(CAS),and the National Astronomical Observatories,CAS(NAOC),reported in Nature As...A team of researchers from the Beijing Normal University,the Institute of High Energy Physics(IHEP)under the Chinese Academy of Sciences(CAS),and the National Astronomical Observatories,CAS(NAOC),reported in Nature Astronomy on January 23,2025 their discovery of an X-ray flash about 12.5 billion lightyears away.The signals burst out only 1.2 billion years after the Big Bang,when our 13.8-billion-year-old universe was still in its infancy,and a science satellite swiftly recorded them.展开更多
Primordial black holes(PBHs) offer a compelling candidate for dark matter. The production of PBHs through well-tested and accepted physical processes is highly worthy of investigation. This work highlights the role of...Primordial black holes(PBHs) offer a compelling candidate for dark matter. The production of PBHs through well-tested and accepted physical processes is highly worthy of investigation. This work highlights the role of turbulences in the very early universe in sustaining intense and persistent fluctuations in energy or mass density,which could provide a natural mechanism for PBH formation in the primordial universe. We analyze the mass range and abundance of PBHs produced in the magnetohydrodynamic turbulence induced by the electroweak phase transition. Remarkably, we find that the mass range of the produced PBHs falls within the most viable“asteroid mass” window from the present-day observations, and within natural parameter regions their abundance can be sufficiently large. These findings suggest that PBHs produced during magnetohydrodynamic turbulence in the very early universe may comprise a dominant part of dark matter.展开更多
This work aims to investigate the different stability conditions of two scenarios of the inhomogeneous Lemaitre–Tolman–Bond model of the universe with holographic dark energy.We considered the Rényi and Tsallis...This work aims to investigate the different stability conditions of two scenarios of the inhomogeneous Lemaitre–Tolman–Bond model of the universe with holographic dark energy.We considered the Rényi and Tsallis holographic models of interacting dark energy.These holographic models are investigated using the IR cutoff that equals the Hubble horizon.Various stability conditions of these models have been investigated to understand how much these models can tell us about the recent and future epochs of the universe in comparison with the cosmological constant model,orΛCDM model.The conditions of violating the cosmological energy conditions have been studied.The evolution of the entropy and its first and second derivatives have been calculated and plotted for these holographic models.This gives an idea of how far these models satisfy the generalized second law of thermodynamics and hence have thermodynamical stability.The dynamical stability is studied for these evolved models,which give us glimpses of the dynamical stability at different phases of its evolution.We focus on investigating the stability in recent and near future times up to z≤-4.Further investigation of stability has been obtained by studying the evolved sound speed squared parameter for these models,which gave us a final and decisive evaluation of the stability of these models.展开更多
Attribute-Based Encryption(ABE)has emerged as a fundamental access control mechanism in data sharing,enabling data owners to define flexible access policies.A critical aspect of ABE is key revocation,which plays a piv...Attribute-Based Encryption(ABE)has emerged as a fundamental access control mechanism in data sharing,enabling data owners to define flexible access policies.A critical aspect of ABE is key revocation,which plays a pivotal role in maintaining security.However,existing key revocation mechanisms face two major challenges:(1)High overhead due to ciphertext and key updates,primarily stemming from the reliance on revocation lists during attribute revocation,which increases computation and communication costs.(2)Limited universality,as many attribute revocation mechanisms are tailored to specific ABE constructions,restricting their broader applicability.To address these challenges,we propose LUAR(Lightweight and Universal Attribute Revocation),a novel revocation mechanism that leverages Intel Software Guard Extensions(SGX)while minimizing its inherent limitations.Given SGX’s constrained memory(≈90 MB in a personal computer)and susceptibility to side-channel attacks,we carefully manage its usage to reduce reliance while mitigating potential collusion risks between cloud service providers and users.To evaluate LUAR’s lightweight and universality,we integrate it with the classic BSW07 scheme,which can be seamlessly replaced with other ABE constructions.Experimental results demonstrate that LUAR enables secure attribute revocation with low computation and communication overhead.The processing time within the SGX environment remains stable at approximately 55 ms,regardless of the complexity of access policies,ensuring no additional storage or computational burden on SGX.Compared to the Hardware-based Revocable Attribute-Based Encryption(HR-ABE)scheme(IEEE S&P 2024),LUAR incurs a slightly higher computational cost within SGX;however,the overall time from initiating a data request to obtaining plaintext is shorter.As access policies grow more complex,LUAR’s advantages become increasingly evident,showcasing its superior efficiency and broader applicability.展开更多
Objective:To determine the prevalence of bullying among university students in Jordan.The study also aims to identify potential predictors of bullying within the context of university students in Jordan.Methods:A cros...Objective:To determine the prevalence of bullying among university students in Jordan.The study also aims to identify potential predictors of bullying within the context of university students in Jordan.Methods:A cross-sectional study using a convenience sampling method was conducted with 350 university students from 3 institutions(2 public and 1 private),who par ticipated in this study.Data were collected through a self-repor ted questionnaire.Data analysis employed descriptive statistics,and multivariate linear regression was executed through the SPSS program(version 26)(IBM Corporation,Armonk,New York,United States)at 5% level of significance.Results:The findings revealed that 30% of the surveyed students reported never experiencing bullying,41.1% indicated rare exposure,20% reported occasional bullying,4.3% noted frequent exposure,and 4.6% reported constant exposure.Statistical analysis identified university and academic year as significant predictors of bullying.The university exhibited significance(B=-0.403,P≤0.05),while the academic year was also a significant predictor(B=0.213,P≤0.05).Conclusions:Given the prevalence and predictors identified,this study recommends the implementation of policies in universities to safeguard students from bullying.These policies should specifically target the most affected individuals.展开更多
In aluminum electrolytic process, the variables affect the current efficiency and the stability of electrolysis cells. AIF3 addition and aluminum tapping volume are two important factors that affect economic benefits ...In aluminum electrolytic process, the variables affect the current efficiency and the stability of electrolysis cells. AIF3 addition and aluminum tapping volume are two important factors that affect economic benefits of aluminum electrolytic production. Fuzzy logic provides a suitable mechanism to describe the relationship between the process variables and the current efficiency. Fuzzy expert system based on Mamdani fuzzy inference process for aluminum electrolysis was adopted to adjust A1F3 addition and aluminum tapping volume. A novel variable universe approach was applied in the system to solve the problem that different electrolysis cells have different universes of variables. The system was applied to 300 kA aluminum electrolysis cells in a aluminum plant. Experimental results showed that the electrolyte temperature was kept stably between 945 and 955℃, the current efficiency reached 93.5%, and the DC power consumption was 13 000 kW.h per ton aluminum.展开更多
The universe is vast and when we look at the sky, its parameters (dimensions, mass, and age) seems limitless. Lemaître proposed that the universe began from a primeval-atom [1] which was later ironically nic...The universe is vast and when we look at the sky, its parameters (dimensions, mass, and age) seems limitless. Lemaître proposed that the universe began from a primeval-atom [1] which was later ironically nicknamed by Hoyle “Big Bang” in a BBC broadcast in 1949 [2]. From general relativity, Einstein proposed a cosmological model [3] with a spatially finite universe. He assumed a uniform distribution of matter in a huge 4-D sphere. Even if his equations were showing that the universe was either contracting or expanding, Einstein introduced the “cosmological constant” in his equation to force the universe to be static (being consistent with the general way of thinking of his time). In 1929, from observations of galaxies, Hubble found that the universe was expanding. From that moment, Einstein discarded his cosmological constant as an unnecessary fudge factor. Many cosmological models have been built over time. Each of them excels in explaining some aspects of the universe. We consider that the global topology of the universe is not known, but making the assumptions that it is relatively homogenous and isotropic, its extrapolated local topology leads us to some global “apparent” parameters. From our new cosmological model, we calculate the main parameters of the universe which are its apparent mass mu, its apparent curving radius Ru, its apparent age Tu and the “quantum of speed” εv. The quantum of speed is a new notion in physics. It is the smallest speed increment that may exist. For metrology purposes, we calculate these parameters from the most precise physics’ parameters available.展开更多
Rough set theory has a very good effect in information processing and knowledge discovery.In an information table,the current scholars regard all objects as a universe,and then establish various rough set models.Howev...Rough set theory has a very good effect in information processing and knowledge discovery.In an information table,the current scholars regard all objects as a universe,and then establish various rough set models.However,in the analysis of many data problems,it is more reasonable to select parts of objects which are useful to us or can meet the actual needs as a universe.Therefore,in order to make up for the deficiency of traditional models,a new model is introduced from the perspective of variable universe.Then,some interesting properties of this model,such as approximation sets,reduct of attributes and maximum part of universe,are discussed.Through the study of this paper,it can be seen that the model developed in our paper is not only more accurate but also more effective in describing uncertain knowledge.展开更多
In the proposed light-dark dual universe, the light universe is the observable universe with light and kinetic energy that fueled the Big Bang, and the dark universe without light and kinetic energy has been observed ...In the proposed light-dark dual universe, the light universe is the observable universe with light and kinetic energy that fueled the Big Bang, and the dark universe without light and kinetic energy has been observed as dark energy since about 9 billion years after the Big Bang. The light-dark dual universe started from the zero-energy universe through the four-stage cyclic transformation. Emerging from the zero-energy universe, the four-stage transformation consists of the 11D (dimensional) positive-negative energy dual membrane universe, the 10D positive-negative energy dual string universe, the 10D positive-negative energy dual particle universe, and the 4D (light)-variable D (dark) positive-negative energy dual particle asymmetrical universe. The transformation can then be reversed back to the zero-energy universe through the reverse four-stage transformation. The light universe is an observable four-dimensional universe started with the inflation and the Big Bang, and the dark universe is a variable dimensional universe from 10D to 4D. The dark universe could be observed as dark energy only when the dark universe turned into a four-dimensional universe. The four-stage transformation explains the four force fields in our universe. The theoretical calculated percentages of dark energy, dark matter, and baryonic matter are 72.8. 22.7, and 4.53, respectively, in nearly complete agreement with observed 72.8, 22.7, and 4.56, respectively. According to the calculation, dark energy started in 4.47 billion years ago in agreement with the observed 4.71 ± 0.98 billion years ago. The zero-energy cyclic universe is based on the space-object structures.展开更多
All things in the universe possess a state and characteristics of state, resultantly in presence of space-time, which is perceived by human beings. An outlook of space-time is shaped in human by perceiving the existen...All things in the universe possess a state and characteristics of state, resultantly in presence of space-time, which is perceived by human beings. An outlook of space-time is shaped in human by perceiving the existence and change of objects. The state space is all state characteristics exhibited in objects whilst the state time refers to the duration of an object＇s state. The time is a spatial property and not an independent dimension. The state space-time is a unity of internal and external space-time. The internal space-time is stemmed from the overall internal forces and internal energies and is a covert space-time. The external space-time refers to a space-time manifested by the external characteristics and movement of an object and is an overt space-time. In physics, there are four kinds of forces and four state space-times： bonding force and three-dimensional space-time; strong interaction of exchangeable n meson and two-dimensional space-time; quark confinement and one-dimensional space-time; and weak interaction and zero-dimensional space-time. The universe is constituted by dissimilar state space-times. Newton space-time is a three-dimensional state space-time; Einstein＇s theory of relativity is a two-dimensional state space-time. Newton and Einstein were different observers. Temporal and spatial perception of human is dependent upon human＇s intemal energy and quality. Through Qigong exercises, the human is able to enter the three-dimensional, two-dimensional, one-dimensional and zero-dimensional space-times. The relativity theory of human body will solve the time problems at the interplanetary voyage of astronauts.展开更多
There are many automatic organization phenomena and automatic organization unities in the universe. The automatic organization whole refers to a life body with the thinking. The thinking is the core of automatic organ...There are many automatic organization phenomena and automatic organization unities in the universe. The automatic organization whole refers to a life body with the thinking. The thinking is the core of automatic organization. The thinking is at eternal restless motion and binds to substances. The universe, organism and society are the automatic organization unities or life systems with the thinking. The thinking can perceive, attract, drive, organize and control all individuals and it is a force of life structure or universal gravitation and universal repulsion. The thinking has a life structure, a template and dynamic of entity-life＇s automatic organization. Life body has five dynamic systems： the thinking motion and information flow, breathing motion, closed-loop current （particle flow） and energy flow, interaction among state-varying, state-stabilizing and control organizations and active ＆ automatic chemical-physical reactions, cardiac pulsation and active motion and transportation. Human, galaxies and society can change from low to high energy state initiatively. This is realized by controlling the desires of life entity via the thinking and breathing motions and by altering the body＇s binding forces dominating the life entity （in turn, by bond force, strong interaction and quark confinement）. All forces in the universe present in the universe of life： force of the thinking-universal gravitation and universal repulsion, electromagnetic interaction, bond force, strong interaction, quark confinement and weak interaction. Under the automatic organization of the thinking, these forces bind into a 4-season＇ whole. The united state of these forces is controlled by the thinking and breathing motion, which is capable of changing from 3-, 2- and 1-dimensional states to a 0-dimensional state.展开更多
To unify the four known fundamental forces and provide an explanation for the origin and the evolution of the universe are two long-term goals of theoretical physics. Here a “universe collapse model” has been propos...To unify the four known fundamental forces and provide an explanation for the origin and the evolution of the universe are two long-term goals of theoretical physics. Here a “universe collapse model” has been proposed. The universe consists of Matter and No-matter. No-matter is the universal energy that constructs a consistent universe field, presenting a spiral wave motion at the speed of light at the small scale. The partial collapse of the universal energy forms the particles of the universal energy in a variety of sizes, which are called as the elementary particles. These elementary particles form atom and matter, which construct the galaxies. The collapse of the universe field induces the formation of the universe collapse potential (UCP) and universe collapse force (UCF), and the later is represented by four different aspects of the fundamental forces at the large or small scales. The mathematical equation and the derivation of UCP and UCF are described, and possible experimental tests are also suggested. Therefore, this new model may give a novel explanation for the unification of four fundamental forces and the origin and the evolution of the universe.展开更多
We present the transition of the universe from the early decelerating phase to the current accelerating phase with viscous fluid and time-dependent cosmological constant (A) as a source of matter in Bianchi- V spaceti...We present the transition of the universe from the early decelerating phase to the current accelerating phase with viscous fluid and time-dependent cosmological constant (A) as a source of matter in Bianchi- V spacetime.To study the transit behaviour of the universe,we assume the scale factor as an increasing function of time,which generates a time-dependent deceleration parameter (DP).The study revesls that the cosmological term does not change its fundamental nature for ε =const and ε =ε(t),where ε is the coefficient of bulk viscosity.The A(t)is found to be positive and is a decreasing function of time.The same behavior was observed during recent supernovae observations.The physical behaviour of the universe is discussed in detail.展开更多
Known models of the Universe development are discussed in the present work. At present it is not possible to state what model is true among the suggested ones because all models are based on the assumptions a validity...Known models of the Universe development are discussed in the present work. At present it is not possible to state what model is true among the suggested ones because all models are based on the assumptions a validity of which is scarcely determined. There are plenty of reasons, and the most important ones are impossibility of experiments performance on a global scale, very short time of nature study and low accuracy of determination of fundamental phy- sical constants to check their possible drift. In the most of models the intellect is an unnecessary attribute. Mankind is only an inner insignificant observer in the Universe. Small changes which Humanity can produce on the Earth don’t modify our planet on a global scale. However besides changes in the material world Mankind can create intellectual valuables. Large information content can be stored, integrate and process using computers. We have no any principle restrictions in advance of the com- puter engineering. Therefore we propose a new model of the Universe development which is based on the increasing facilities of our Mankind. In this model the Earth is considered as an analogue of supercomputer. Under certain circumstances Mankind is ready to carry out information processing for other civilizations, but such civilizations have not yet been found. The Creators of the Universe could be other customers. Computer-like model of the Universe suggests a communication with the Creators in future for execution of their calculation orders. However this model is not complete because of lack of high rate of information transfer for long distances.展开更多
文摘This paper aims to define the concept of time and justify its properties within the universal context, shedding new light on the nature of time. By employing the concept of the extrinsic universe, the paper explains the observable universe as the three-dimensional surface of a four-dimensional 3-sphere (hypersphere), expanding at the speed of light. This expansion process gives rise to what we perceive as time and its associated aspects, providing a novel interpretation of time as a geometric property emerging from the dynamics of the universe’s expansion. The work offers insights into how this extrinsic perspective can address phenomena such as the universe’s accelerated expansion and dark matter, aligning the model with current observational data.
文摘During the past few decades, it has become clear that the distribution, sizes, and masses of cosmic structures are best described as fractal rather than homogeneous. This means that an entirely different formalism is needed to replace the standard perturbation model of structure formation. Recently, we have been developing a model of cosmology that accounts for a large number of the observed properties of the universe. A key component of this model is that fractal structures that later regulated the creation of both matter and radiation came into existence during the initial Planck-era inflation. Initially, the vacuum was the only existence and since time, distance, and energy were uncertain, its only property, the curvature (or energy), was most likely distributed randomly. Everything that happened after the Planck era can be described by the known laws of physics so the remaining fundamental problem is to discover how such a random beginning could organize itself into the hierarchy of highly non-random self-similar structures on all length scales that are necessary to explain the existence of all cosmic structures. In this paper, we present a variation of the standard sandpile model that points to a solution. Incidental to our review of the distributions of cosmic structures, we discovered that the apparent transition from a fractal to a homogeneous distribution of structures at a distance of about 150 Mpc is a consequence of the finite size of the universe rather than a change in the underlying statistics of the distributions.
文摘Dispersion measure in an FRB’s signal is produced by the photons of the radio waves interacting with the free electrons in the IGM. In New Tired Light (NTL), redshifts are produced by the photons of light interacting with these self-same electrons and so, one would expect a direct relationship between the DM of an FRB and the redshift of the host galaxy. However, workers in this field assume expansion and weight the DM by dividing it by the scale factor (1 + z) to allow for expansion. Once this weighting is removed, it was predicted back in 2016 (when the first FRB was localized) and later presented at a conference and published in the proceedings that, as more FRB’s were localized, a graph of DM versus ln(1 + z) would be a straight line of gradient (mec/2hre) or 7.32 × 1025 m−2 in SI units. The original paper had twenty-four data points but this has risen significantly to sixty-four useable FRB’s and so this corrigendum updates that paper so that all sixty-four are used. The data give a straight-line graph of gradient 7.12 × 1025 m−2, a difference of 3% from (mec/2hre) predicted nine years earlier.
基金Sponsored by CAS,the Chinese Ministry of Science and Technology and the National Natural Science Foundation of China,the project is anticipated to break through on the frontiers of fundamental physics,astrophysics and cosmology.
文摘In July,the Ali CMB Polariza〓〓tion Telescope(AliCPT)of〓〓ficially released high-quality maps of 150 GHz radiation from the Moon and Jupiter.The quality of these images not only validates the exceptional performance of the core instrument of AliCPT-1 but also signifies the successful completion of its first-stage con〓〓struction.
文摘A team of researchers from the Beijing Normal University,the Institute of High Energy Physics(IHEP)under the Chinese Academy of Sciences(CAS),and the National Astronomical Observatories,CAS(NAOC),reported in Nature Astronomy on January 23,2025 their discovery of an X-ray flash about 12.5 billion lightyears away.The signals burst out only 1.2 billion years after the Big Bang,when our 13.8-billion-year-old universe was still in its infancy,and a science satellite swiftly recorded them.
基金supported by the International Partnership Program of the Chinese Academy of Sciences (Grant No.025GJHZ2023106GC)。
文摘Primordial black holes(PBHs) offer a compelling candidate for dark matter. The production of PBHs through well-tested and accepted physical processes is highly worthy of investigation. This work highlights the role of turbulences in the very early universe in sustaining intense and persistent fluctuations in energy or mass density,which could provide a natural mechanism for PBH formation in the primordial universe. We analyze the mass range and abundance of PBHs produced in the magnetohydrodynamic turbulence induced by the electroweak phase transition. Remarkably, we find that the mass range of the produced PBHs falls within the most viable“asteroid mass” window from the present-day observations, and within natural parameter regions their abundance can be sufficiently large. These findings suggest that PBHs produced during magnetohydrodynamic turbulence in the very early universe may comprise a dominant part of dark matter.
文摘This work aims to investigate the different stability conditions of two scenarios of the inhomogeneous Lemaitre–Tolman–Bond model of the universe with holographic dark energy.We considered the Rényi and Tsallis holographic models of interacting dark energy.These holographic models are investigated using the IR cutoff that equals the Hubble horizon.Various stability conditions of these models have been investigated to understand how much these models can tell us about the recent and future epochs of the universe in comparison with the cosmological constant model,orΛCDM model.The conditions of violating the cosmological energy conditions have been studied.The evolution of the entropy and its first and second derivatives have been calculated and plotted for these holographic models.This gives an idea of how far these models satisfy the generalized second law of thermodynamics and hence have thermodynamical stability.The dynamical stability is studied for these evolved models,which give us glimpses of the dynamical stability at different phases of its evolution.We focus on investigating the stability in recent and near future times up to z≤-4.Further investigation of stability has been obtained by studying the evolved sound speed squared parameter for these models,which gave us a final and decisive evaluation of the stability of these models.
基金support from the National Key Research and Development Program of China(Grant No.2021YFF0704102)the Chongqing Education Commission Key Project of Science and Technology Research(Grant No.KJZD-K202400610)the Chongqing Natural Science Foundation General Project(Grant No.CSTB2025NSCQ-GPX1263).
文摘Attribute-Based Encryption(ABE)has emerged as a fundamental access control mechanism in data sharing,enabling data owners to define flexible access policies.A critical aspect of ABE is key revocation,which plays a pivotal role in maintaining security.However,existing key revocation mechanisms face two major challenges:(1)High overhead due to ciphertext and key updates,primarily stemming from the reliance on revocation lists during attribute revocation,which increases computation and communication costs.(2)Limited universality,as many attribute revocation mechanisms are tailored to specific ABE constructions,restricting their broader applicability.To address these challenges,we propose LUAR(Lightweight and Universal Attribute Revocation),a novel revocation mechanism that leverages Intel Software Guard Extensions(SGX)while minimizing its inherent limitations.Given SGX’s constrained memory(≈90 MB in a personal computer)and susceptibility to side-channel attacks,we carefully manage its usage to reduce reliance while mitigating potential collusion risks between cloud service providers and users.To evaluate LUAR’s lightweight and universality,we integrate it with the classic BSW07 scheme,which can be seamlessly replaced with other ABE constructions.Experimental results demonstrate that LUAR enables secure attribute revocation with low computation and communication overhead.The processing time within the SGX environment remains stable at approximately 55 ms,regardless of the complexity of access policies,ensuring no additional storage or computational burden on SGX.Compared to the Hardware-based Revocable Attribute-Based Encryption(HR-ABE)scheme(IEEE S&P 2024),LUAR incurs a slightly higher computational cost within SGX;however,the overall time from initiating a data request to obtaining plaintext is shorter.As access policies grow more complex,LUAR’s advantages become increasingly evident,showcasing its superior efficiency and broader applicability.
文摘Objective:To determine the prevalence of bullying among university students in Jordan.The study also aims to identify potential predictors of bullying within the context of university students in Jordan.Methods:A cross-sectional study using a convenience sampling method was conducted with 350 university students from 3 institutions(2 public and 1 private),who par ticipated in this study.Data were collected through a self-repor ted questionnaire.Data analysis employed descriptive statistics,and multivariate linear regression was executed through the SPSS program(version 26)(IBM Corporation,Armonk,New York,United States)at 5% level of significance.Results:The findings revealed that 30% of the surveyed students reported never experiencing bullying,41.1% indicated rare exposure,20% reported occasional bullying,4.3% noted frequent exposure,and 4.6% reported constant exposure.Statistical analysis identified university and academic year as significant predictors of bullying.The university exhibited significance(B=-0.403,P≤0.05),while the academic year was also a significant predictor(B=0.213,P≤0.05).Conclusions:Given the prevalence and predictors identified,this study recommends the implementation of policies in universities to safeguard students from bullying.These policies should specifically target the most affected individuals.
基金Project (2009BAE85B00) supported by the National Key Technology R&D Program of ChinaProject (PHR20100509) supported by Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality, China
文摘In aluminum electrolytic process, the variables affect the current efficiency and the stability of electrolysis cells. AIF3 addition and aluminum tapping volume are two important factors that affect economic benefits of aluminum electrolytic production. Fuzzy logic provides a suitable mechanism to describe the relationship between the process variables and the current efficiency. Fuzzy expert system based on Mamdani fuzzy inference process for aluminum electrolysis was adopted to adjust A1F3 addition and aluminum tapping volume. A novel variable universe approach was applied in the system to solve the problem that different electrolysis cells have different universes of variables. The system was applied to 300 kA aluminum electrolysis cells in a aluminum plant. Experimental results showed that the electrolyte temperature was kept stably between 945 and 955℃, the current efficiency reached 93.5%, and the DC power consumption was 13 000 kW.h per ton aluminum.
文摘The universe is vast and when we look at the sky, its parameters (dimensions, mass, and age) seems limitless. Lemaître proposed that the universe began from a primeval-atom [1] which was later ironically nicknamed by Hoyle “Big Bang” in a BBC broadcast in 1949 [2]. From general relativity, Einstein proposed a cosmological model [3] with a spatially finite universe. He assumed a uniform distribution of matter in a huge 4-D sphere. Even if his equations were showing that the universe was either contracting or expanding, Einstein introduced the “cosmological constant” in his equation to force the universe to be static (being consistent with the general way of thinking of his time). In 1929, from observations of galaxies, Hubble found that the universe was expanding. From that moment, Einstein discarded his cosmological constant as an unnecessary fudge factor. Many cosmological models have been built over time. Each of them excels in explaining some aspects of the universe. We consider that the global topology of the universe is not known, but making the assumptions that it is relatively homogenous and isotropic, its extrapolated local topology leads us to some global “apparent” parameters. From our new cosmological model, we calculate the main parameters of the universe which are its apparent mass mu, its apparent curving radius Ru, its apparent age Tu and the “quantum of speed” εv. The quantum of speed is a new notion in physics. It is the smallest speed increment that may exist. For metrology purposes, we calculate these parameters from the most precise physics’ parameters available.
基金supported by the National Natural Science Foundation of China(Nos.61976254,61772002)the Natural Science Foundation of Fujian Province(No.2020J01707)National Fund Cultivation program of Jimei University(No.ZP2020056).
文摘Rough set theory has a very good effect in information processing and knowledge discovery.In an information table,the current scholars regard all objects as a universe,and then establish various rough set models.However,in the analysis of many data problems,it is more reasonable to select parts of objects which are useful to us or can meet the actual needs as a universe.Therefore,in order to make up for the deficiency of traditional models,a new model is introduced from the perspective of variable universe.Then,some interesting properties of this model,such as approximation sets,reduct of attributes and maximum part of universe,are discussed.Through the study of this paper,it can be seen that the model developed in our paper is not only more accurate but also more effective in describing uncertain knowledge.
文摘In the proposed light-dark dual universe, the light universe is the observable universe with light and kinetic energy that fueled the Big Bang, and the dark universe without light and kinetic energy has been observed as dark energy since about 9 billion years after the Big Bang. The light-dark dual universe started from the zero-energy universe through the four-stage cyclic transformation. Emerging from the zero-energy universe, the four-stage transformation consists of the 11D (dimensional) positive-negative energy dual membrane universe, the 10D positive-negative energy dual string universe, the 10D positive-negative energy dual particle universe, and the 4D (light)-variable D (dark) positive-negative energy dual particle asymmetrical universe. The transformation can then be reversed back to the zero-energy universe through the reverse four-stage transformation. The light universe is an observable four-dimensional universe started with the inflation and the Big Bang, and the dark universe is a variable dimensional universe from 10D to 4D. The dark universe could be observed as dark energy only when the dark universe turned into a four-dimensional universe. The four-stage transformation explains the four force fields in our universe. The theoretical calculated percentages of dark energy, dark matter, and baryonic matter are 72.8. 22.7, and 4.53, respectively, in nearly complete agreement with observed 72.8, 22.7, and 4.56, respectively. According to the calculation, dark energy started in 4.47 billion years ago in agreement with the observed 4.71 ± 0.98 billion years ago. The zero-energy cyclic universe is based on the space-object structures.
文摘All things in the universe possess a state and characteristics of state, resultantly in presence of space-time, which is perceived by human beings. An outlook of space-time is shaped in human by perceiving the existence and change of objects. The state space is all state characteristics exhibited in objects whilst the state time refers to the duration of an object＇s state. The time is a spatial property and not an independent dimension. The state space-time is a unity of internal and external space-time. The internal space-time is stemmed from the overall internal forces and internal energies and is a covert space-time. The external space-time refers to a space-time manifested by the external characteristics and movement of an object and is an overt space-time. In physics, there are four kinds of forces and four state space-times： bonding force and three-dimensional space-time; strong interaction of exchangeable n meson and two-dimensional space-time; quark confinement and one-dimensional space-time; and weak interaction and zero-dimensional space-time. The universe is constituted by dissimilar state space-times. Newton space-time is a three-dimensional state space-time; Einstein＇s theory of relativity is a two-dimensional state space-time. Newton and Einstein were different observers. Temporal and spatial perception of human is dependent upon human＇s intemal energy and quality. Through Qigong exercises, the human is able to enter the three-dimensional, two-dimensional, one-dimensional and zero-dimensional space-times. The relativity theory of human body will solve the time problems at the interplanetary voyage of astronauts.
文摘There are many automatic organization phenomena and automatic organization unities in the universe. The automatic organization whole refers to a life body with the thinking. The thinking is the core of automatic organization. The thinking is at eternal restless motion and binds to substances. The universe, organism and society are the automatic organization unities or life systems with the thinking. The thinking can perceive, attract, drive, organize and control all individuals and it is a force of life structure or universal gravitation and universal repulsion. The thinking has a life structure, a template and dynamic of entity-life＇s automatic organization. Life body has five dynamic systems： the thinking motion and information flow, breathing motion, closed-loop current （particle flow） and energy flow, interaction among state-varying, state-stabilizing and control organizations and active ＆ automatic chemical-physical reactions, cardiac pulsation and active motion and transportation. Human, galaxies and society can change from low to high energy state initiatively. This is realized by controlling the desires of life entity via the thinking and breathing motions and by altering the body＇s binding forces dominating the life entity （in turn, by bond force, strong interaction and quark confinement）. All forces in the universe present in the universe of life： force of the thinking-universal gravitation and universal repulsion, electromagnetic interaction, bond force, strong interaction, quark confinement and weak interaction. Under the automatic organization of the thinking, these forces bind into a 4-season＇ whole. The united state of these forces is controlled by the thinking and breathing motion, which is capable of changing from 3-, 2- and 1-dimensional states to a 0-dimensional state.
文摘To unify the four known fundamental forces and provide an explanation for the origin and the evolution of the universe are two long-term goals of theoretical physics. Here a “universe collapse model” has been proposed. The universe consists of Matter and No-matter. No-matter is the universal energy that constructs a consistent universe field, presenting a spiral wave motion at the speed of light at the small scale. The partial collapse of the universal energy forms the particles of the universal energy in a variety of sizes, which are called as the elementary particles. These elementary particles form atom and matter, which construct the galaxies. The collapse of the universe field induces the formation of the universe collapse potential (UCP) and universe collapse force (UCF), and the later is represented by four different aspects of the fundamental forces at the large or small scales. The mathematical equation and the derivation of UCP and UCF are described, and possible experimental tests are also suggested. Therefore, this new model may give a novel explanation for the unification of four fundamental forces and the origin and the evolution of the universe.
文摘We present the transition of the universe from the early decelerating phase to the current accelerating phase with viscous fluid and time-dependent cosmological constant (A) as a source of matter in Bianchi- V spacetime.To study the transit behaviour of the universe,we assume the scale factor as an increasing function of time,which generates a time-dependent deceleration parameter (DP).The study revesls that the cosmological term does not change its fundamental nature for ε =const and ε =ε(t),where ε is the coefficient of bulk viscosity.The A(t)is found to be positive and is a decreasing function of time.The same behavior was observed during recent supernovae observations.The physical behaviour of the universe is discussed in detail.
文摘Known models of the Universe development are discussed in the present work. At present it is not possible to state what model is true among the suggested ones because all models are based on the assumptions a validity of which is scarcely determined. There are plenty of reasons, and the most important ones are impossibility of experiments performance on a global scale, very short time of nature study and low accuracy of determination of fundamental phy- sical constants to check their possible drift. In the most of models the intellect is an unnecessary attribute. Mankind is only an inner insignificant observer in the Universe. Small changes which Humanity can produce on the Earth don’t modify our planet on a global scale. However besides changes in the material world Mankind can create intellectual valuables. Large information content can be stored, integrate and process using computers. We have no any principle restrictions in advance of the com- puter engineering. Therefore we propose a new model of the Universe development which is based on the increasing facilities of our Mankind. In this model the Earth is considered as an analogue of supercomputer. Under certain circumstances Mankind is ready to carry out information processing for other civilizations, but such civilizations have not yet been found. The Creators of the Universe could be other customers. Computer-like model of the Universe suggests a communication with the Creators in future for execution of their calculation orders. However this model is not complete because of lack of high rate of information transfer for long distances.
