The authors of the existing version of the special theory of relativity had to use the princi-ple of light speed non-exceedance to explain relativistic formulas obtained therein within the space of real numbers. The p...The authors of the existing version of the special theory of relativity had to use the princi-ple of light speed non-exceedance to explain relativistic formulas obtained therein within the space of real numbers. The principle implied existence of only our visible universe and absence of physical content in imaginary numbers. However, since the principle is just a postulate, i.e. an unproven assumption, it has always carried little credibility. The paper refutes the principle by the experimentally proven principle of physical reality of imagi-nary numbers. As follows from the principle of physical reality of imaginary numbers, relativistic formulas of the existing version of the STR are wrong and incorrectly ex-plained, and conclusions drawn from them are misguided. In other words, this version is incorrect1 and, thus, the STR was not actually created in the 20th century. Moreover, it could not be created in the 20th century, as its creation required experimental data ob-tained in the 21st century. The paper provides an alternative version of the STR contain-ing relativistic formulas corrected given experimental data obtained in the 21st century. These formulas imply that instead of the Monoverse, whose existence is supposed in the existing version of the STR, there is a Multiverse, whose universes are mutually invisible (and the invisibility is explainable) and therefore it has been referred to as hidden. The paper explains that existence of invisible universes of the hidden Multiverse gives rise to the phenomenon of dark matter and dark energy that is actually a sort of optical effect (however, not electromagnetic, but gravitational), a shadow, rather than some physical substance2. It also explains that existence of other invisible universes outside the hidden Multiverse gives rise to the phenomenon of dark space. Invisible universes are claimed to really exist, which can be experimentally proved by astronomical observations in portals, where universes not visible outside portals become partially visible. Therefore, constella-tions observed in the starry sky inside the portals are different from those observed in our visible universe. The alternative version of the special theory of relativity can also suc-cessfully solve other issues of astrophysics. In particular, it can explain where antimatter is located and why it does not annihilate with matter, as well as where tachyons are locat-ed and why they don’t violate the principle of causality, etc.展开更多
The article shows that the special theory of relativity (STR) was not actually created in the 20th century, since: 1) the relativistic formulas presented therein are incorrect;2) the relativistic formulas presented th...The article shows that the special theory of relativity (STR) was not actually created in the 20th century, since: 1) the relativistic formulas presented therein are incorrect;2) the relativistic formulas presented therein are explained incorrectly using the incorrect principle of light speed non-exceedance refuted in the article;3) the relativistic formulas presented therein rise to incorrect conclusions about physical unreality of imaginary numbers and existence of only our visible universe. Moreover, the STR could not even have been created in the 20th century since: 1) experimental data on the six-dimensional space of our hidden Multiverse, which allowed to derive the correct relativistic formulas, were obtained by the WMAP and Planck spacecraft only in the 21st century;2) the principle of physical reality of imaginary numbers, which allowed to refute the principle of not exceeding the speed of light and correctly explain the new relativistic formulas, was experimentally proved only in the 21st century. Therefore, the new relativistic formulas obtained given these circumstances allow to state that, in addition to our visible universe, there are numerous other mutually invisible universes, which together form the hidden Multiverse. Existence of invisible universes explains the phenomenon of dark matter and dark energy. Their existence also explains why antimatter in the hidden Multiverse does not annihilate with matter, and tachyons do not violate the principle of causality. The existence of these invisible universes can be proved by astronomical observations in the portals, since in them the constellations of the starry sky will differ from the constellations observed from existing observatories on Earth.展开更多
The proposed cyclic universes model based on the split division algebras accounts for the inflation, the Big Bang, gravity, dark energy, dark matter, the standard model, and the masses of all elementary particles. The...The proposed cyclic universes model based on the split division algebras accounts for the inflation, the Big Bang, gravity, dark energy, dark matter, the standard model, and the masses of all elementary particles. The split algebras (complex quaternion and complex octonion) as the Furey model generate the fixed spacetime dimension number for the observable universe with the fixed 4-dimensional spacetime (4D) standard model particles and the oscillating spacetime dimension number for the oscillating universes (hidden or dark energy) with the oscillation between 11D and 11D through 10D and between 10D and 10D through 4D. 11D has the lowest rest mass, the highest speed of light, and the highest vacuum energy, while 4D has the highest rest mass, the lowest (observed) speed of light, and zero vacuum energy. In the cyclic universes model, the universes start with the positive-energy and the negative-energy 11D membrane-antimembrane dual universes from the zero-energy inter-universal void, and are followed by the transformation of the 11D membrane-antimembrane dual universes into the 10D string-antistring dual universes and the external dual gravities as in the Randall-Sundrum model, resulting in the four equal and separate universes consisting of the positive-energy 10D universe, the positive-energy external gravity, the negative-energy 10D universe, and the negative-energy external gravity. Under the fixed spacetime dimension number, the positive-energy 10D universe is transformed into 4D standard model particles through the inflation and the Big Bang. Dark matter is the right-handed neutrino, exactly five times of baryonic matter in total mass in the universe. Under the oscillating spacetime dimension number, the other three universes oscillate between 10D and 10D through 4D, resulting in the hidden universes when D > 4 and dark energy (the maximum dark energy = 3/4 = 75%) when D = 4. Eventually, all four universes return to the 10D universes.展开更多
The two universes multi-granularity fuzzy rough set model is an effective tool for handling uncertainty problems between two domains with the help of binary fuzzy relations. This article applies the idea of neighborho...The two universes multi-granularity fuzzy rough set model is an effective tool for handling uncertainty problems between two domains with the help of binary fuzzy relations. This article applies the idea of neighborhood rough sets to two universes multi-granularity fuzzy rough sets, and discusses the two-universes multi-granularity neighborhood fuzzy rough set model. Firstly, the upper and lower approximation operators are defined in the two universes multi-granularity neighborhood fuzzy rough set model. Secondly, the properties of the upper and lower approximation operators are discussed. Finally, the properties of the two universes multi-granularity neighborhood fuzzy rough set model are verified through case studies.展开更多
We study string cosmological models with attached particles in LRS BI type space time. The dynamical and physical properties of such universes are studied, and the possibility that during the evolution of the universe...We study string cosmological models with attached particles in LRS BI type space time. The dynamical and physical properties of such universes are studied, and the possibility that during the evolution of the universe the strings disappear, leaving only the particles, is also discussed. It is found that bulk viscosity plays a large role in the evolution of the universe. In these models we find critical instances of when there was a "Bounce". The studied models are found to be of an inflationary type, and since a desirable feature of a meaningful string cosmological model is the presence of an inflationary epoch in the very early stages of evolution, our models can be thought of as realistic universes.展开更多
The procedure similar to an ordinary quantum held theory in curved spacetime is applied to study the Bianchi type-I universes with a radiation field source.The Wheeler-De Witt equation satisfied by the cosmological wa...The procedure similar to an ordinary quantum held theory in curved spacetime is applied to study the Bianchi type-I universes with a radiation field source.The Wheeler-De Witt equation satisfied by the cosmological wave function is found.After the wave function was regarded as a universe held in the minisuperspace,not only the difficulty in a probabilistic interpretation in the quantum cosmology can be circumvented,but also the conclusion of the multiple production of universes is obtained,and the average number of various universes created from‘nothing’is estimated.展开更多
Under the harmonic condition the Einstein and the static de Sitter universes in relativistic cosmology are again solved.According to the view that the harmonic condition is a physical one,the size of the static de Sit...Under the harmonic condition the Einstein and the static de Sitter universes in relativistic cosmology are again solved.According to the view that the harmonic condition is a physical one,the size of the static de Sitter universe is infinite.展开更多
The Bianchi type- III and Kantowski-Sachs (KS) Universes filled with dark energy from a wet dark fluid has been considered. A new equation of state for the dark energy component of the universe has been used. It is mo...The Bianchi type- III and Kantowski-Sachs (KS) Universes filled with dark energy from a wet dark fluid has been considered. A new equation of state for the dark energy component of the universe has been used. It is modeled on the equation of state ρ=γ(ρ -ρ *) , which can describe a liquid, for example water. The exact solutions to the corresponding field equations are obtained in quadrature form. The solution for constant deceleration parameter have been studied in detail for power-law and exponential forms both. The case γ = 0,γ =1,and γ =1/3have been also analysed.展开更多
Considering five dimensional plane symmetric metric, we discuss a model universe with different situations, by solving the modified Einstein field equations within the framework of Lyra geometry. We obtain many intere...Considering five dimensional plane symmetric metric, we discuss a model universe with different situations, by solving the modified Einstein field equations within the framework of Lyra geometry. We obtain many interesting realistic solutions governing the present day model of the universe. Physical and kinematical properties of the models are discussed in detail.展开更多
"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields ofscience sponsored by Jilin University and administrated by the Ministry of Education of the People's Repu..."Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields ofscience sponsored by Jilin University and administrated by the Ministry of Education of the People's Republic of China.The journal started publication in 1955.The original name at starting publicationwas"Journal of Natural Science of Northeast People University",which was changed into"ActaScientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.展开更多
I come from Slovenia,a small but ambitious country from Central Europe.I study at the Faculty of Electrical Engineering at the University of Ljublgana.I have the privilege of being one of the first young ambassadors o...I come from Slovenia,a small but ambitious country from Central Europe.I study at the Faculty of Electrical Engineering at the University of Ljublgana.I have the privilege of being one of the first young ambassadors of standardization not only in Slovenia but of this generation across the entire world.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
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
To help university students know more about standards,and attract them to par ticipate in s tandardization ac tivities,the International Standardization Youth Star Competition was initiated by the International Standa...To help university students know more about standards,and attract them to par ticipate in s tandardization ac tivities,the International Standardization Youth Star Competition was initiated by the International Standardization Outstanding Contribution Award Foundation(ISOCAF)in 2023,and has been held since then for three consecutive years in China.The 2025 Competition attracted 236 teams nationwide who demonstrated great enthusiasm for engaging in the standardization undertaking.The SPECIAL REPORT column presents the series reports on the competition,which is expected to inspire more young minds to step forward,innovate with purpose,and shape a future where standards unite ambition with impact.展开更多
The deep integration of artificial intelligence technology and agricultural industry has pushed smart agriculture into a new stage of"AI+scenario",and put forward a transformation requirement for the talent ...The deep integration of artificial intelligence technology and agricultural industry has pushed smart agriculture into a new stage of"AI+scenario",and put forward a transformation requirement for the talent cultivation of smart agriculture major in universities from"technology application"to"intelligent innovation".In response to the problems of insufficient AI integration,lack of contextualization,and insufficient collaboration between industry and education in the traditional"technology+"practical course system,this paper takes the smart agriculture major at Yulin Normal University as an example to construct a"AI+agriculture"practical course reconstruction framework and propose a four-dimensional transformation path of"goal-content-mode-evaluation".Through the practical exploration of modular curriculum design,scenario based practical design,integration of industry and education,and intelligent evaluation reform,a practical teaching system with local application-oriented university characteristics has been formed,providing a reference example for the cultivation of smart agriculture professionals under the background of new agricultural science.展开更多
At inference time,deep neural networks are susceptible to backdoor attacks,which can produce attackercontrolled outputs when inputs contain carefully crafted triggers.Existing defense methods often focus on specific a...At inference time,deep neural networks are susceptible to backdoor attacks,which can produce attackercontrolled outputs when inputs contain carefully crafted triggers.Existing defense methods often focus on specific attack types or incur high costs,such as data cleaning or model fine-tuning.In contrast,we argue that it is possible to achieve effective and generalizable defense without removing triggers or incurring high model-cleaning costs.Fromthe attacker’s perspective and based on characteristics of vulnerable neuron activation anomalies,we propose an Adaptive Feature Injection(AFI)method for black-box backdoor detection.AFI employs a pre-trained image encoder to extract multi-level deep features and constructs a dynamic weight fusionmechanism for precise identification and interception of poisoned samples.Specifically,we select the control samples with the largest feature differences fromthe clean dataset via feature-space analysis,and generate blended sample pairs with the test sample using dynamic linear interpolation.The detection statistic is computed by measuring the divergence G(x)in model output responses.We systematically evaluate the effectiveness of AFI against representative backdoor attacks,including BadNets,Blend,WaNet,and IAB,on three benchmark datasets:MNIST,CIFAR-10,and ImageNet.Experimental results show that AFI can effectively detect poisoned samples,achieving average detection rates of 95.20%,94.15%,and 86.49%on these datasets,respectively.Compared with existing methods,AFI demonstrates strong cross-domain generalization ability and robustness to unknown attacks.展开更多
"Happy birthday to you,happy birthday,dearteacher!"On a bright,sunny mid-summer afternoon,the tune of the birthday song reverberated through a plain-looking classroom in University Padjadjaran's Faculty ..."Happy birthday to you,happy birthday,dearteacher!"On a bright,sunny mid-summer afternoon,the tune of the birthday song reverberated through a plain-looking classroom in University Padjadjaran's Faculty of Communication Sciences in Bandung,Indonesia.The opening session of the communication theory course coincided with one of the instructors'50th birthday.Athe end of the class,the students burst into singing,wishing their teacher a splendid start to her next decade.展开更多
We investigate numerically the effects of long-range temporal and spatial correlations based on the rescaled distributions of the squared interface width W^(2)(L, t) and the interface height h(x, t)in the(1+1)-dimensi...We investigate numerically the effects of long-range temporal and spatial correlations based on the rescaled distributions of the squared interface width W^(2)(L, t) and the interface height h(x, t)in the(1+1)-dimensional Kardar-Parisi-Zhang(KPZ) growth system within the early growth regime. Through extensive numerical simulations, we find that long-range temporally correlated noise does not significantly impact the distribution form of the interface width. Generally,W^(2)(L, t) approximately obeys a lognormal distribution when the temporal correlation exponentθ ≥0. On the other hand, the effects of long-range spatially correlated noise are evidently different from the temporally correlated case. Our results show that, when the spatial correlation exponent ρ ≤ 0.20, the distribution forms of W^(2)(L, t) approach the lognormal distribution, and when ρ > 0.20, the distribution becomes more asymmetric, steep, and fat-tailed, and tends to an unknown distribution form. As a comparison, probability distributions of the interface height are also provided in the temporally and spatially correlated KPZ system, exhibiting quite different characteristics from each other within the whole correlated strengths. For the temporal correlation, the height distributions follow Tracy-Widom Gaussian orthogonal ensemble(TW-GOE) when θ → 0, and with increasing θ, the height distributions crossover continuously to an unknown distribution. However, for the spatial correlation, the height distributions gradually transition from the TW-GOE distribution to the standard Gaussian form.展开更多
We search for the stochastic gravitational-wave background(SGWB) predicted by pre-Big-Bang(PBB) cosmology using data from the first three observing runs of Advanced LIGO and Advanced Virgo. PBB cosmology proposes an a...We search for the stochastic gravitational-wave background(SGWB) predicted by pre-Big-Bang(PBB) cosmology using data from the first three observing runs of Advanced LIGO and Advanced Virgo. PBB cosmology proposes an alternative to cosmic inflation where the Universe evolves from a weak-coupling, low-curvature state to the hot Big Bang through a high-curvature bounce phase, predicting a distinctive SGWB spectrum. We perform a Bayesian analysis of the cross-correlation data to constrain the model parameters characterizing the PBB spectrum. We find no evidence for a PBB-induced SGWB, with a Bayes factor of 0.03 between the PBB and noise-only model, strongly favoring the noise-only hypothesis. Our analysis establishes a lower bound β ≳-0.19 at 95% confidence level, which is compatible with the theoretical requirement β ≥ 0 for a smooth bounce transition. While we do not detect a signal,our constraints remain consistent with the basic theoretical framework of PBB cosmology,demonstrating the potential of gravitational-wave observations to test early Universe theories.展开更多
文摘The authors of the existing version of the special theory of relativity had to use the princi-ple of light speed non-exceedance to explain relativistic formulas obtained therein within the space of real numbers. The principle implied existence of only our visible universe and absence of physical content in imaginary numbers. However, since the principle is just a postulate, i.e. an unproven assumption, it has always carried little credibility. The paper refutes the principle by the experimentally proven principle of physical reality of imagi-nary numbers. As follows from the principle of physical reality of imaginary numbers, relativistic formulas of the existing version of the STR are wrong and incorrectly ex-plained, and conclusions drawn from them are misguided. In other words, this version is incorrect1 and, thus, the STR was not actually created in the 20th century. Moreover, it could not be created in the 20th century, as its creation required experimental data ob-tained in the 21st century. The paper provides an alternative version of the STR contain-ing relativistic formulas corrected given experimental data obtained in the 21st century. These formulas imply that instead of the Monoverse, whose existence is supposed in the existing version of the STR, there is a Multiverse, whose universes are mutually invisible (and the invisibility is explainable) and therefore it has been referred to as hidden. The paper explains that existence of invisible universes of the hidden Multiverse gives rise to the phenomenon of dark matter and dark energy that is actually a sort of optical effect (however, not electromagnetic, but gravitational), a shadow, rather than some physical substance2. It also explains that existence of other invisible universes outside the hidden Multiverse gives rise to the phenomenon of dark space. Invisible universes are claimed to really exist, which can be experimentally proved by astronomical observations in portals, where universes not visible outside portals become partially visible. Therefore, constella-tions observed in the starry sky inside the portals are different from those observed in our visible universe. The alternative version of the special theory of relativity can also suc-cessfully solve other issues of astrophysics. In particular, it can explain where antimatter is located and why it does not annihilate with matter, as well as where tachyons are locat-ed and why they don’t violate the principle of causality, etc.
文摘The article shows that the special theory of relativity (STR) was not actually created in the 20th century, since: 1) the relativistic formulas presented therein are incorrect;2) the relativistic formulas presented therein are explained incorrectly using the incorrect principle of light speed non-exceedance refuted in the article;3) the relativistic formulas presented therein rise to incorrect conclusions about physical unreality of imaginary numbers and existence of only our visible universe. Moreover, the STR could not even have been created in the 20th century since: 1) experimental data on the six-dimensional space of our hidden Multiverse, which allowed to derive the correct relativistic formulas, were obtained by the WMAP and Planck spacecraft only in the 21st century;2) the principle of physical reality of imaginary numbers, which allowed to refute the principle of not exceeding the speed of light and correctly explain the new relativistic formulas, was experimentally proved only in the 21st century. Therefore, the new relativistic formulas obtained given these circumstances allow to state that, in addition to our visible universe, there are numerous other mutually invisible universes, which together form the hidden Multiverse. Existence of invisible universes explains the phenomenon of dark matter and dark energy. Their existence also explains why antimatter in the hidden Multiverse does not annihilate with matter, and tachyons do not violate the principle of causality. The existence of these invisible universes can be proved by astronomical observations in the portals, since in them the constellations of the starry sky will differ from the constellations observed from existing observatories on Earth.
文摘The proposed cyclic universes model based on the split division algebras accounts for the inflation, the Big Bang, gravity, dark energy, dark matter, the standard model, and the masses of all elementary particles. The split algebras (complex quaternion and complex octonion) as the Furey model generate the fixed spacetime dimension number for the observable universe with the fixed 4-dimensional spacetime (4D) standard model particles and the oscillating spacetime dimension number for the oscillating universes (hidden or dark energy) with the oscillation between 11D and 11D through 10D and between 10D and 10D through 4D. 11D has the lowest rest mass, the highest speed of light, and the highest vacuum energy, while 4D has the highest rest mass, the lowest (observed) speed of light, and zero vacuum energy. In the cyclic universes model, the universes start with the positive-energy and the negative-energy 11D membrane-antimembrane dual universes from the zero-energy inter-universal void, and are followed by the transformation of the 11D membrane-antimembrane dual universes into the 10D string-antistring dual universes and the external dual gravities as in the Randall-Sundrum model, resulting in the four equal and separate universes consisting of the positive-energy 10D universe, the positive-energy external gravity, the negative-energy 10D universe, and the negative-energy external gravity. Under the fixed spacetime dimension number, the positive-energy 10D universe is transformed into 4D standard model particles through the inflation and the Big Bang. Dark matter is the right-handed neutrino, exactly five times of baryonic matter in total mass in the universe. Under the oscillating spacetime dimension number, the other three universes oscillate between 10D and 10D through 4D, resulting in the hidden universes when D > 4 and dark energy (the maximum dark energy = 3/4 = 75%) when D = 4. Eventually, all four universes return to the 10D universes.
文摘The two universes multi-granularity fuzzy rough set model is an effective tool for handling uncertainty problems between two domains with the help of binary fuzzy relations. This article applies the idea of neighborhood rough sets to two universes multi-granularity fuzzy rough sets, and discusses the two-universes multi-granularity neighborhood fuzzy rough set model. Firstly, the upper and lower approximation operators are defined in the two universes multi-granularity neighborhood fuzzy rough set model. Secondly, the properties of the upper and lower approximation operators are discussed. Finally, the properties of the two universes multi-granularity neighborhood fuzzy rough set model are verified through case studies.
文摘We study string cosmological models with attached particles in LRS BI type space time. The dynamical and physical properties of such universes are studied, and the possibility that during the evolution of the universe the strings disappear, leaving only the particles, is also discussed. It is found that bulk viscosity plays a large role in the evolution of the universe. In these models we find critical instances of when there was a "Bounce". The studied models are found to be of an inflationary type, and since a desirable feature of a meaningful string cosmological model is the presence of an inflationary epoch in the very early stages of evolution, our models can be thought of as realistic universes.
文摘The procedure similar to an ordinary quantum held theory in curved spacetime is applied to study the Bianchi type-I universes with a radiation field source.The Wheeler-De Witt equation satisfied by the cosmological wave function is found.After the wave function was regarded as a universe held in the minisuperspace,not only the difficulty in a probabilistic interpretation in the quantum cosmology can be circumvented,but also the conclusion of the multiple production of universes is obtained,and the average number of various universes created from‘nothing’is estimated.
文摘Under the harmonic condition the Einstein and the static de Sitter universes in relativistic cosmology are again solved.According to the view that the harmonic condition is a physical one,the size of the static de Sitter universe is infinite.
文摘The Bianchi type- III and Kantowski-Sachs (KS) Universes filled with dark energy from a wet dark fluid has been considered. A new equation of state for the dark energy component of the universe has been used. It is modeled on the equation of state ρ=γ(ρ -ρ *) , which can describe a liquid, for example water. The exact solutions to the corresponding field equations are obtained in quadrature form. The solution for constant deceleration parameter have been studied in detail for power-law and exponential forms both. The case γ = 0,γ =1,and γ =1/3have been also analysed.
文摘Considering five dimensional plane symmetric metric, we discuss a model universe with different situations, by solving the modified Einstein field equations within the framework of Lyra geometry. We obtain many interesting realistic solutions governing the present day model of the universe. Physical and kinematical properties of the models are discussed in detail.
文摘"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields ofscience sponsored by Jilin University and administrated by the Ministry of Education of the People's Republic of China.The journal started publication in 1955.The original name at starting publicationwas"Journal of Natural Science of Northeast People University",which was changed into"ActaScientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.
文摘I come from Slovenia,a small but ambitious country from Central Europe.I study at the Faculty of Electrical Engineering at the University of Ljublgana.I have the privilege of being one of the first young ambassadors of standardization not only in Slovenia but of this generation across the entire world.
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To help university students know more about standards,and attract them to par ticipate in s tandardization ac tivities,the International Standardization Youth Star Competition was initiated by the International Standardization Outstanding Contribution Award Foundation(ISOCAF)in 2023,and has been held since then for three consecutive years in China.The 2025 Competition attracted 236 teams nationwide who demonstrated great enthusiasm for engaging in the standardization undertaking.The SPECIAL REPORT column presents the series reports on the competition,which is expected to inspire more young minds to step forward,innovate with purpose,and shape a future where standards unite ambition with impact.
基金Supported by the Autonomous Region-level Research and Practice Projects for New Engineering,New Medicine,New Agriculture,and New Humanities of Guangxi Department of Education(XNK202409)the Undergraduate Teaching Reform Project of Guangxi Higher Education(2024JGB332+1 种基金2024JGA304)the Guangxi Degree and Graduate Education Reform Project(JGY2025382).
文摘The deep integration of artificial intelligence technology and agricultural industry has pushed smart agriculture into a new stage of"AI+scenario",and put forward a transformation requirement for the talent cultivation of smart agriculture major in universities from"technology application"to"intelligent innovation".In response to the problems of insufficient AI integration,lack of contextualization,and insufficient collaboration between industry and education in the traditional"technology+"practical course system,this paper takes the smart agriculture major at Yulin Normal University as an example to construct a"AI+agriculture"practical course reconstruction framework and propose a four-dimensional transformation path of"goal-content-mode-evaluation".Through the practical exploration of modular curriculum design,scenario based practical design,integration of industry and education,and intelligent evaluation reform,a practical teaching system with local application-oriented university characteristics has been formed,providing a reference example for the cultivation of smart agriculture professionals under the background of new agricultural science.
基金supported by the National Natural Science Foundation of China Grant(No.61972133)Project of Leading Talents in Science and Technology Innovation for Thousands of People Plan in Henan Province Grant(No.204200510021)the Key Research and Development Plan Special Project of Henan Province Grant(No.241111211400).
文摘At inference time,deep neural networks are susceptible to backdoor attacks,which can produce attackercontrolled outputs when inputs contain carefully crafted triggers.Existing defense methods often focus on specific attack types or incur high costs,such as data cleaning or model fine-tuning.In contrast,we argue that it is possible to achieve effective and generalizable defense without removing triggers or incurring high model-cleaning costs.Fromthe attacker’s perspective and based on characteristics of vulnerable neuron activation anomalies,we propose an Adaptive Feature Injection(AFI)method for black-box backdoor detection.AFI employs a pre-trained image encoder to extract multi-level deep features and constructs a dynamic weight fusionmechanism for precise identification and interception of poisoned samples.Specifically,we select the control samples with the largest feature differences fromthe clean dataset via feature-space analysis,and generate blended sample pairs with the test sample using dynamic linear interpolation.The detection statistic is computed by measuring the divergence G(x)in model output responses.We systematically evaluate the effectiveness of AFI against representative backdoor attacks,including BadNets,Blend,WaNet,and IAB,on three benchmark datasets:MNIST,CIFAR-10,and ImageNet.Experimental results show that AFI can effectively detect poisoned samples,achieving average detection rates of 95.20%,94.15%,and 86.49%on these datasets,respectively.Compared with existing methods,AFI demonstrates strong cross-domain generalization ability and robustness to unknown attacks.
文摘"Happy birthday to you,happy birthday,dearteacher!"On a bright,sunny mid-summer afternoon,the tune of the birthday song reverberated through a plain-looking classroom in University Padjadjaran's Faculty of Communication Sciences in Bandung,Indonesia.The opening session of the communication theory course coincided with one of the instructors'50th birthday.Athe end of the class,the students burst into singing,wishing their teacher a splendid start to her next decade.
文摘We investigate numerically the effects of long-range temporal and spatial correlations based on the rescaled distributions of the squared interface width W^(2)(L, t) and the interface height h(x, t)in the(1+1)-dimensional Kardar-Parisi-Zhang(KPZ) growth system within the early growth regime. Through extensive numerical simulations, we find that long-range temporally correlated noise does not significantly impact the distribution form of the interface width. Generally,W^(2)(L, t) approximately obeys a lognormal distribution when the temporal correlation exponentθ ≥0. On the other hand, the effects of long-range spatially correlated noise are evidently different from the temporally correlated case. Our results show that, when the spatial correlation exponent ρ ≤ 0.20, the distribution forms of W^(2)(L, t) approach the lognormal distribution, and when ρ > 0.20, the distribution becomes more asymmetric, steep, and fat-tailed, and tends to an unknown distribution form. As a comparison, probability distributions of the interface height are also provided in the temporally and spatially correlated KPZ system, exhibiting quite different characteristics from each other within the whole correlated strengths. For the temporal correlation, the height distributions follow Tracy-Widom Gaussian orthogonal ensemble(TW-GOE) when θ → 0, and with increasing θ, the height distributions crossover continuously to an unknown distribution. However, for the spatial correlation, the height distributions gradually transition from the TW-GOE distribution to the standard Gaussian form.
基金supported by the National Natural Science Foundation of China(Grants No.12405055 and No.12347111)supported by the National Natural Science Foundation of China(Grant No.12505054 and 12433001)+5 种基金the China Postdoctoral Science Foundation(Grant No.2023M741148)the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20240458)supported by the National Natural Science Foundation of China under Grant No.12405056supported by the National Natural Science Foundation of China under Grant No.12405057the Natural Science Foundation of Hunan Province under Grant No.2025JJ40006the Innovative Research Group of Hunan Province under Grant No.2024JJ1006。
文摘We search for the stochastic gravitational-wave background(SGWB) predicted by pre-Big-Bang(PBB) cosmology using data from the first three observing runs of Advanced LIGO and Advanced Virgo. PBB cosmology proposes an alternative to cosmic inflation where the Universe evolves from a weak-coupling, low-curvature state to the hot Big Bang through a high-curvature bounce phase, predicting a distinctive SGWB spectrum. We perform a Bayesian analysis of the cross-correlation data to constrain the model parameters characterizing the PBB spectrum. We find no evidence for a PBB-induced SGWB, with a Bayes factor of 0.03 between the PBB and noise-only model, strongly favoring the noise-only hypothesis. Our analysis establishes a lower bound β ≳-0.19 at 95% confidence level, which is compatible with the theoretical requirement β ≥ 0 for a smooth bounce transition. While we do not detect a signal,our constraints remain consistent with the basic theoretical framework of PBB cosmology,demonstrating the potential of gravitational-wave observations to test early Universe theories.
