Published proof test coverage(PTC)estimates for emergency shutdown valves(ESDVs)show only moderate agreement and are predominantly opinion-based.A Failure Modes,Effects,and Diagnostics Analysis(FMEDA)was undertaken us...Published proof test coverage(PTC)estimates for emergency shutdown valves(ESDVs)show only moderate agreement and are predominantly opinion-based.A Failure Modes,Effects,and Diagnostics Analysis(FMEDA)was undertaken using component failure rate data to predict PTC for a full stroke test and a partial stroke test.Given the subjective and uncertain aspects of the FMEDA approach,specifically the selection of component failure rates and the determination of the probability of detecting failure modes,a Fuzzy Inference System(FIS)was proposed to manage the data,addressing the inherent uncertainties.Fuzzy inference systems have been used previously for various FMEA type assessments,but this is the first time an FIS has been employed for use with FMEDA.ESDV PTC values were generated from both the standard FMEDA and the fuzzy-FMEDA approaches using data provided by FMEDA experts.This work demonstrates that fuzzy inference systems can address the subjectivity inherent in FMEDA data,enabling reliable estimates of ESDV proof test coverage for both full and partial stroke tests.This facilitates optimized maintenance planning while ensuring safety is not compromised.展开更多
In the age of big data,ensuring data privacy while enabling efficient encrypted data retrieval has become a critical challenge.Traditional searchable encryption schemes face difficulties in handling complex semantic q...In the age of big data,ensuring data privacy while enabling efficient encrypted data retrieval has become a critical challenge.Traditional searchable encryption schemes face difficulties in handling complex semantic queries.Additionally,they typically rely on honest but curious cloud servers,which introduces the risk of repudiation.Furthermore,the combined operations of search and verification increase system load,thereby reducing performance.Traditional verification mechanisms,which rely on complex hash constructions,suffer from low verification efficiency.To address these challenges,this paper proposes a blockchain-based contextual semantic-aware ciphertext retrieval scheme with efficient verification.Building on existing single and multi-keyword search methods,the scheme uses vector models to semantically train the dataset,enabling it to retain semantic information and achieve context-aware encrypted retrieval,significantly improving search accuracy.Additionally,a blockchain-based updatable master-slave chain storage model is designed,where the master chain stores encrypted keyword indexes and the slave chain stores verification information generated by zero-knowledge proofs,thus balancing system load while improving search and verification efficiency.Finally,an improved non-interactive zero-knowledge proof mechanism is introduced,reducing the computational complexity of verification and ensuring efficient validation of search results.Experimental results demonstrate that the proposed scheme offers stronger security,balanced overhead,and higher search verification efficiency.展开更多
电影歌曲作为整部电影的有机组成部分,其重要性不可小觑,一首好的歌曲能达到锦上添花的观影效果。目前国内对电影歌词的研究,大多集中在音乐学、美学、文学等语言学之外的领域,从功能语言学的角度对电影歌曲的解读尚且不多。本文拟以系...电影歌曲作为整部电影的有机组成部分,其重要性不可小觑,一首好的歌曲能达到锦上添花的观影效果。目前国内对电影歌词的研究,大多集中在音乐学、美学、文学等语言学之外的领域,从功能语言学的角度对电影歌曲的解读尚且不多。本文拟以系统功能语法理论为指导,从语境、经验功能、人际功能着手解析电影《相助》片尾曲《The Living Proof》,以期丰富系统功能语法的研究内容,为电影歌词的分析提供新的视角,帮助观影者深度理解影片主题。展开更多
The differences among the extended Canetti ＆ Krawezyk 2007 model （ECK2007） and other four models, i.e., the Bellare ＆ Rogaway （1993, 1995）models （BR93,BR95）, the Bellare, Pointcheval ＆ Rogaway （2000） model ...The differences among the extended Canetti ＆ Krawezyk 2007 model （ECK2007） and other four models, i.e., the Bellare ＆ Rogaway （1993, 1995）models （BR93,BR95）, the Bellare, Pointcheval ＆ Rogaway （2000） model （BPR2000） and the Canetti ＆ Krawczyk （2001） model （CK2001） are given. The relative strength of security among these models is analyzed. To support the implication or non-implication relation among these models, the formal proof or the counter-example is provided.展开更多
The next-generation RAN,known as Open Radio Access Network(ORAN),allows for several advantages,including cost-effectiveness,network flexibility,and interoperability.Now ORAN applications,utilising machine learning(ML)...The next-generation RAN,known as Open Radio Access Network(ORAN),allows for several advantages,including cost-effectiveness,network flexibility,and interoperability.Now ORAN applications,utilising machine learning(ML)and artificial intelligence(AI)techniques,have become standard practice.The need for Federated Learning(FL)for ML model training in ORAN environments is heightened by the modularised structure of the ORAN architecture and the shortcomings of conventional ML techniques.However,the traditional plaintext model update sharing of FL in multi-BS contexts is susceptible to privacy violations such as deep-leakage gradient assaults and inference.Therefore,this research presents a novel blockchain-assisted improved cryptographic privacy-preserving federated learning(BICPPFL)model,with the help of ORAN,to safely carry out federated learning and protect privacy.This model improves on the conventional masking technique for sharing model parameters by adding new characteristics.These features include the choice of distributed aggregators,validation for final model aggregation,and individual validation for BSs.To manage the security and privacy of FL processes,a combined homomorphic proxy-reencryption(HPReE)and lattice-cryptographic method(HPReEL)has been used.The upgraded delegated proof of stake(Up-DPoS)consensus protocol,which will provide quick validation of model exchanges and protect against malicious attacks,is employed for effective consensus across blockchain nodes.Without sacrificing performance metrics,the BICPPFL model strengthens privacy and adds security layers while facilitating the transfer of sensitive data across several BSs.The framework is deployed on top of a Hyperledger Fabric blockchain to evaluate its effectiveness.The experimental findings prove the reliability and privacy-preserving capability of the BICPPFL model.展开更多
In this paper we point out that the proofs of Chain Rule in many intensively used textbooks are not strict an construct anexa mple of a composite function f(u) which is differentiable with respects t o the independe...In this paper we point out that the proofs of Chain Rule in many intensively used textbooks are not strict an construct anexa mple of a composite function f(u) which is differentiable with respects t o the independednt variable u, but is not differentiable with respect to the dependent variable u=g(x). A strict proof of Chain Rule is presented. Incon sistency of the form and content of Chain Rule is disclosed.展开更多
The effect of Ce on ignition point of AZ91D magnesium alloy chips was studied. For the AZ91D and the AZ91D-xCe magnesium alloys, changing the sizes of the chips in the range of 58 - 270 μm has a limited influence on ...The effect of Ce on ignition point of AZ91D magnesium alloy chips was studied. For the AZ91D and the AZ91D-xCe magnesium alloys, changing the sizes of the chips in the range of 58 - 270 μm has a limited influence on ignition point, however, the shift of the content of Ce has much effect on ignition point. Increasing the Ce content, x from 0.15 to 0.25, the ignition point increases with increasing of Ce; however, x from 0.25 to 0.45, the ignition point decreases with increasing of Ce. By the addition of Ce of 0.25 %. the ignition point is raised by 43℃.展开更多
Non-Interactive Zero-Knowledge(NIZK for short) proofs are fascinating and extremely useful in many security protocols. In this paper,a new group signature scheme,decisional linear assumption group signature(DLAGS for ...Non-Interactive Zero-Knowledge(NIZK for short) proofs are fascinating and extremely useful in many security protocols. In this paper,a new group signature scheme,decisional linear assumption group signature(DLAGS for short) with NIZK proofs is proposed which can prove and sign the multiple values rather than individual bits based on DLIN assumption. DLAGS does not need to interact between the verifier and issuer,which can decrease the communication times and storage cost compared with the existing interactive group signature schemes. We prove and sign the blocks of messages instead of limiting the proved message to only one bit(0 or 1) in the conventional non-interactive zero-knowledge proof system,and we also prove that our scheme satisfy the property of anonymity,unlinkability and traceability. Finally,our scheme is compared with the other scheme(Benoitt's scheme) which is also based on the NIZK proofs system and the DLIN assumption,and the results show that our scheme requires fewer members of groups and computational times.展开更多
Good ignition-proof principle and mechanical properties were realized in Mg-Y-Ca-Zr alloy system.By adding Y and Ca elements,the ignition point of Mg-3.5Y-0.8Ca alloy was improved to over 1173 K,and the alloy could be...Good ignition-proof principle and mechanical properties were realized in Mg-Y-Ca-Zr alloy system.By adding Y and Ca elements,the ignition point of Mg-3.5Y-0.8Ca alloy was improved to over 1173 K,and the alloy could be melted in air without any protections.The ef-fect of Zr addition on the microstructures and mechanical properties of Mg-3.5Y-0.8Ca alloys were investigated,and Mg-3.5%Y-0.8%Ca-0.4%Zr alloy had good comprehensive properties with tensile strength of 190 MPa and elongation of 11%.Auger electron spectros-copy(AES)and X-ray diffraction(XRD)analysis revealed that the oxide film formed on the surface of Mg-3.5Y-0.8Ca alloy was mainly composed of Y2O3.Thermogravimetric measurements in dry air indicated that the oxidation dynamics curves measured at 773,873 and 973 K followed the cubic law.Moreover,the semiconductor characteristic of Y2O3 film and its effect on ignition-proof properties of Magnesium al-loys were discussed from the viewpoint of electrochemistry.展开更多
Provable security has become a popular approach for analyzing the security of cryptographic protocols.However,writing and verifying proofs by hand are prone to errors.This paper advocates the automatic security proof ...Provable security has become a popular approach for analyzing the security of cryptographic protocols.However,writing and verifying proofs by hand are prone to errors.This paper advocates the automatic security proof framework with sequences of games.We make slight modifications to Blanchet's calculus to make it easy for parsing the initial game.The main contribution of this work is that it introduces algebraic properties with observational equivalences to automatic security proofs,and thus can deal with some practical cryptographic schemes with hard problems.We illustrate the use of algebraic properties in the framework by proving the semantic security of the ElGamal encryption scheme.展开更多
Riemann hypothesis (RH) is a difficult problem. So far one doesn’t know how to go about it. Studying ζ and using analysis method likely are two incor-rect guides. Actually, a unique hope may study Riemann function &...Riemann hypothesis (RH) is a difficult problem. So far one doesn’t know how to go about it. Studying ζ and using analysis method likely are two incor-rect guides. Actually, a unique hope may study Riemann function <img alt="" src="Edit_8fcdfff5-6b95-42a4-8f47-2cabe2723dfc.bmp" />, <img alt="" src="Edit_6ce3a4bd-4c68-49e5-aabe-dec3e904e282.bmp" />, <img alt="" src="Edit_29ea252e-a81e-4b21-a41c-09209c780bb2.bmp" /> by geometric analysis, which has the symmetry: v=0 if β=0, and basic expression <img alt="" src="Edit_bc7a883f-312d-44fd-bcdd-00f25c92f80a.bmp" />. We show that |u| is single peak in each root-interval <img alt="" src="Edit_d7ca54c7-4866-4419-a4bd-cbb808b365af.bmp" /> of u for fixed β ∈(0,1/2]. Using the slope u<sub>t</sub>, we prove that v has opposite signs at two end-points of I<sub>j</sub>. There surely exists an inner point such that , so {|u|,|v|/β} form a local peak-valley structure, and have positive lower bound <img alt="" src="Edit_bac1a5f6-673e-49b6-892c-5adff0141376.bmp" /> in I<sub>j</sub>. Because each t must lie in some I<sub>j</sub>, then ||ξ|| > 0 is valid for any t (i.e. RH is true). Using the positivity <img alt="" src="Edit_83c3d2cf-aa7e-4aba-89f5-0eb44659918a.bmp" /> of Lagarias (1999), we show the strict monotone <img alt="" src="Edit_87eb4e9e-bc7b-43e3-b316-5dcf0efaf0d5.bmp" /> for β > β<sub>0</sub> ≥ 0 , and the peak-valley structure is equiva-lent to RH, which may be the geometric model expected by Bombieri (2000). This research follows Liuhui’s methodology: “Computing can detect the un-known and method”.展开更多
An RFID (Radio-Frequency IDentification) system provides the mechanism to identify tags to readers and then to execute specific RFID-enabled applications. In those applications, secure protocols using lightweight cryp...An RFID (Radio-Frequency IDentification) system provides the mechanism to identify tags to readers and then to execute specific RFID-enabled applications. In those applications, secure protocols using lightweight cryptography need to be developed and the privacy of tags must be ensured. In 2010, Batina et al. proposed a privacy-preserving grouping proof protocol for RFID based on ECC (Elliptic Curve Cryptography) in public-key cryptosystem. In the next year, Lv et al. had shown that Batina et al.’s protocol was insecure against the tracking attack such that the privacy of tags did not be preserved properly. Then they proposed a revised protocol based on Batina et al.’s work. Their revised protocol was claimed to have all security properties and resisted tracking attack. But in this paper, we prove that Lv et al.’s protocol cannot work properly. Then we propose a new version protocol with some nonce to satisfy the functions of Batina et al.’s privacy-preserving grouping proof protocol. Further we try the tracing attack made by Lv et al. on our protocol and prove our protocol can resist this attack to recover the untraceability.展开更多
Nowadays, multi-functional materials are desperately required for adapting the complex environment, which urges us to take more factors into consideration. Here, we proposed a broadband microwave absorber with multi-f...Nowadays, multi-functional materials are desperately required for adapting the complex environment, which urges us to take more factors into consideration. Here, we proposed a broadband microwave absorber with multi-functionality such as optically transparent, thermal insulating and soundproof properties. Using indium tin oxide(ITO) based metamaterial, the device can achieve above 90% microwave absorption from 5.6 GHz to 23 GHz(cover X and Ku band). Moreover, with designed vacuum structure inside, the device is thermal insulating and soundproof. These multi-functional advantages give the absorber more flexibility in electromagnetic shielding and stealth application, which can be potentially applied in windows related industry.展开更多
Background: Nine proteins were identified as putative profibrotic biomarkers in systemic sclerosis (SSc) and an unrelated fibrotic disease in a previously published proteomic study. As the majority of these proteins w...Background: Nine proteins were identified as putative profibrotic biomarkers in systemic sclerosis (SSc) and an unrelated fibrotic disease in a previously published proteomic study. As the majority of these proteins were orphans of commercially available antibodies, the nine proteins were investigated to determine whether binding peptide aptamers of the Stefin A quadruple mutant-Tracy variant (referred to as “affimers”) could be validated by enzyme linked immunosorbant assay (ELISA) to allow the quantification of these candidate biomarkers in the sera of SSc patients. Materials and Methods: Candidate biomarker peptides were analysed by high throughput affimer microarray to identify binding affimers. Two candidate biomarkers were prioritised, and binding affimers were expressed from genetically modified BL21 competent E. coli strains and purified. These affimers were used in indirect ELISA, and then sandwich ELISA formats against the candidate biomarker recombinant proteins osteonectin and pigment epi-thetlium-derived factor (PEDF). Results: 39 affimers were identified as binders for eight of the nine candidate biomarker peptides were by affimer microarray;six for osteonectin and eleven for PEDF. Two of the six and all eleven were able to recognize physiological concentrations (5 and 1 μg·ml﹣1) of osteonectin and PEDF, respectively by indirect ELISA. In sandwich ELISA format: two affimers were able to detect recombinant PEDF;however, the two affimers identified in indirect ELISA were unable to recognise recombinant osteonectin, and were thus hypothesised to bind to osteonectin at the same binding site. Discussion: SSc is currently an orphan of fully validated biomarkers, which is required for the development of stratified medicine in this field. This approach has laid the groundwork for an affimer based on multiplexed assay, to validate biomarkers in the sera of SSc patients in the future.展开更多
The author presents a new approach which is used to solve an important Diophantine problem. An elementary argument is used to furnish another fully transparent proof of Fermat’s Last Theorem. This was first stated by...The author presents a new approach which is used to solve an important Diophantine problem. An elementary argument is used to furnish another fully transparent proof of Fermat’s Last Theorem. This was first stated by Pierre de Fermat in the seventeenth century. It is widely regarded that no elementary proof of this theorem exists. The author provides evidence to dispel this belief.展开更多
This paper introduces a conceptual framework for developing pedagogical games of mathematical proof (PGMP) designed to help non-STEM students learn mathematical reasoning in a playful manner and without “fear”. With...This paper introduces a conceptual framework for developing pedagogical games of mathematical proof (PGMP) designed to help non-STEM students learn mathematical reasoning in a playful manner and without “fear”. Within the constructivist learning paradigm it develops an in-class learning activity where social science students learn the concept of mathematical deduction playfully using toys to construct tables from which formal proofs of propositions are derived without calculations. A PGMP pedagogy quality assurance evaluation method based on fuzzy evaluation mappings capturing learning effectiveness, learning efficiency, and learning satisfaction is introduced. Our results from an in-class experiment show that pedagogical games of mathematical proof help non-STEM students to effectively engage with mathematical reasoning playfully. The results are consistent according to a quality assurance consistency index.展开更多
How to keep cloud data intact and available to users is a problem to be solved. Authenticated skip list is an important data structure used in cloud data integrity verification. How to get the membership proof of the ...How to keep cloud data intact and available to users is a problem to be solved. Authenticated skip list is an important data structure used in cloud data integrity verification. How to get the membership proof of the element in authenticated skip list efficiently is an important part of authentication. Kaouthar Blibech and Alban Gabillon proposed a head proof and a tail proof algorithms for the membership proof of elements in the authenticated skip list. However, the proposed algorithms are uncorrelated each other and need plateau function. We propose a new algorithm for computing the membership proof for elements in the authenticated skip list by using two stacks, one is for storing traversal chain of leaf node, the other is for storing authentication path for the leaf. The proposed algorithm is simple and effective without needing plateau function. It can also be applicable for other similar binary hash trees.展开更多
文摘Published proof test coverage(PTC)estimates for emergency shutdown valves(ESDVs)show only moderate agreement and are predominantly opinion-based.A Failure Modes,Effects,and Diagnostics Analysis(FMEDA)was undertaken using component failure rate data to predict PTC for a full stroke test and a partial stroke test.Given the subjective and uncertain aspects of the FMEDA approach,specifically the selection of component failure rates and the determination of the probability of detecting failure modes,a Fuzzy Inference System(FIS)was proposed to manage the data,addressing the inherent uncertainties.Fuzzy inference systems have been used previously for various FMEA type assessments,but this is the first time an FIS has been employed for use with FMEDA.ESDV PTC values were generated from both the standard FMEDA and the fuzzy-FMEDA approaches using data provided by FMEDA experts.This work demonstrates that fuzzy inference systems can address the subjectivity inherent in FMEDA data,enabling reliable estimates of ESDV proof test coverage for both full and partial stroke tests.This facilitates optimized maintenance planning while ensuring safety is not compromised.
基金supported in part by the National Natural Science Foundation of China under Grant 62262073in part by the Yunnan Provincial Ten Thousand People Program for Young Top Talents under Grant YNWR-QNBJ-2019-237in part by the Yunnan Provincial Major Science and Technology Special Program under Grant 202402AD080002.
文摘In the age of big data,ensuring data privacy while enabling efficient encrypted data retrieval has become a critical challenge.Traditional searchable encryption schemes face difficulties in handling complex semantic queries.Additionally,they typically rely on honest but curious cloud servers,which introduces the risk of repudiation.Furthermore,the combined operations of search and verification increase system load,thereby reducing performance.Traditional verification mechanisms,which rely on complex hash constructions,suffer from low verification efficiency.To address these challenges,this paper proposes a blockchain-based contextual semantic-aware ciphertext retrieval scheme with efficient verification.Building on existing single and multi-keyword search methods,the scheme uses vector models to semantically train the dataset,enabling it to retain semantic information and achieve context-aware encrypted retrieval,significantly improving search accuracy.Additionally,a blockchain-based updatable master-slave chain storage model is designed,where the master chain stores encrypted keyword indexes and the slave chain stores verification information generated by zero-knowledge proofs,thus balancing system load while improving search and verification efficiency.Finally,an improved non-interactive zero-knowledge proof mechanism is introduced,reducing the computational complexity of verification and ensuring efficient validation of search results.Experimental results demonstrate that the proposed scheme offers stronger security,balanced overhead,and higher search verification efficiency.
文摘电影歌曲作为整部电影的有机组成部分,其重要性不可小觑,一首好的歌曲能达到锦上添花的观影效果。目前国内对电影歌词的研究,大多集中在音乐学、美学、文学等语言学之外的领域,从功能语言学的角度对电影歌曲的解读尚且不多。本文拟以系统功能语法理论为指导,从语境、经验功能、人际功能着手解析电影《相助》片尾曲《The Living Proof》,以期丰富系统功能语法的研究内容,为电影歌词的分析提供新的视角,帮助观影者深度理解影片主题。
文摘The differences among the extended Canetti ＆ Krawezyk 2007 model （ECK2007） and other four models, i.e., the Bellare ＆ Rogaway （1993, 1995）models （BR93,BR95）, the Bellare, Pointcheval ＆ Rogaway （2000） model （BPR2000） and the Canetti ＆ Krawczyk （2001） model （CK2001） are given. The relative strength of security among these models is analyzed. To support the implication or non-implication relation among these models, the formal proof or the counter-example is provided.
文摘The next-generation RAN,known as Open Radio Access Network(ORAN),allows for several advantages,including cost-effectiveness,network flexibility,and interoperability.Now ORAN applications,utilising machine learning(ML)and artificial intelligence(AI)techniques,have become standard practice.The need for Federated Learning(FL)for ML model training in ORAN environments is heightened by the modularised structure of the ORAN architecture and the shortcomings of conventional ML techniques.However,the traditional plaintext model update sharing of FL in multi-BS contexts is susceptible to privacy violations such as deep-leakage gradient assaults and inference.Therefore,this research presents a novel blockchain-assisted improved cryptographic privacy-preserving federated learning(BICPPFL)model,with the help of ORAN,to safely carry out federated learning and protect privacy.This model improves on the conventional masking technique for sharing model parameters by adding new characteristics.These features include the choice of distributed aggregators,validation for final model aggregation,and individual validation for BSs.To manage the security and privacy of FL processes,a combined homomorphic proxy-reencryption(HPReE)and lattice-cryptographic method(HPReEL)has been used.The upgraded delegated proof of stake(Up-DPoS)consensus protocol,which will provide quick validation of model exchanges and protect against malicious attacks,is employed for effective consensus across blockchain nodes.Without sacrificing performance metrics,the BICPPFL model strengthens privacy and adds security layers while facilitating the transfer of sensitive data across several BSs.The framework is deployed on top of a Hyperledger Fabric blockchain to evaluate its effectiveness.The experimental findings prove the reliability and privacy-preserving capability of the BICPPFL model.
文摘In this paper we point out that the proofs of Chain Rule in many intensively used textbooks are not strict an construct anexa mple of a composite function f(u) which is differentiable with respects t o the independednt variable u, but is not differentiable with respect to the dependent variable u=g(x). A strict proof of Chain Rule is presented. Incon sistency of the form and content of Chain Rule is disclosed.
文摘The effect of Ce on ignition point of AZ91D magnesium alloy chips was studied. For the AZ91D and the AZ91D-xCe magnesium alloys, changing the sizes of the chips in the range of 58 - 270 μm has a limited influence on ignition point, however, the shift of the content of Ce has much effect on ignition point. Increasing the Ce content, x from 0.15 to 0.25, the ignition point increases with increasing of Ce; however, x from 0.25 to 0.45, the ignition point decreases with increasing of Ce. By the addition of Ce of 0.25 %. the ignition point is raised by 43℃.
基金supported by the National High-Tech Research and Development Plan of China under Grant Nos.863-317-01- 04-99, 2009AA01Z122 (863)the Natural Science Foundation of Shenyang City of China under Grant No. F10-205-1-12
文摘Non-Interactive Zero-Knowledge(NIZK for short) proofs are fascinating and extremely useful in many security protocols. In this paper,a new group signature scheme,decisional linear assumption group signature(DLAGS for short) with NIZK proofs is proposed which can prove and sign the multiple values rather than individual bits based on DLIN assumption. DLAGS does not need to interact between the verifier and issuer,which can decrease the communication times and storage cost compared with the existing interactive group signature schemes. We prove and sign the blocks of messages instead of limiting the proved message to only one bit(0 or 1) in the conventional non-interactive zero-knowledge proof system,and we also prove that our scheme satisfy the property of anonymity,unlinkability and traceability. Finally,our scheme is compared with the other scheme(Benoitt's scheme) which is also based on the NIZK proofs system and the DLIN assumption,and the results show that our scheme requires fewer members of groups and computational times.
基金Project supported by the National Natural Science Foundation of China(50901048,51174143)the fund of the State Key Laboratory of Solidification Processing in NWPU(SKLSP201003)+1 种基金Program for Changjiang Scholar and Innovative Research Team in University(IRT0972)Program for the Top Young Academic Leaders of Higher Learning Institutions of Shanxi and Natural Science Foundation of Shanxi(2010021022-5)
文摘Good ignition-proof principle and mechanical properties were realized in Mg-Y-Ca-Zr alloy system.By adding Y and Ca elements,the ignition point of Mg-3.5Y-0.8Ca alloy was improved to over 1173 K,and the alloy could be melted in air without any protections.The ef-fect of Zr addition on the microstructures and mechanical properties of Mg-3.5Y-0.8Ca alloys were investigated,and Mg-3.5%Y-0.8%Ca-0.4%Zr alloy had good comprehensive properties with tensile strength of 190 MPa and elongation of 11%.Auger electron spectros-copy(AES)and X-ray diffraction(XRD)analysis revealed that the oxide film formed on the surface of Mg-3.5Y-0.8Ca alloy was mainly composed of Y2O3.Thermogravimetric measurements in dry air indicated that the oxidation dynamics curves measured at 773,873 and 973 K followed the cubic law.Moreover,the semiconductor characteristic of Y2O3 film and its effect on ignition-proof properties of Magnesium al-loys were discussed from the viewpoint of electrochemistry.
基金National High Technical Research and Development Program of China(863 program)under Grant No. 2007AA01Z471
文摘Provable security has become a popular approach for analyzing the security of cryptographic protocols.However,writing and verifying proofs by hand are prone to errors.This paper advocates the automatic security proof framework with sequences of games.We make slight modifications to Blanchet's calculus to make it easy for parsing the initial game.The main contribution of this work is that it introduces algebraic properties with observational equivalences to automatic security proofs,and thus can deal with some practical cryptographic schemes with hard problems.We illustrate the use of algebraic properties in the framework by proving the semantic security of the ElGamal encryption scheme.
文摘Riemann hypothesis (RH) is a difficult problem. So far one doesn’t know how to go about it. Studying ζ and using analysis method likely are two incor-rect guides. Actually, a unique hope may study Riemann function <img alt="" src="Edit_8fcdfff5-6b95-42a4-8f47-2cabe2723dfc.bmp" />, <img alt="" src="Edit_6ce3a4bd-4c68-49e5-aabe-dec3e904e282.bmp" />, <img alt="" src="Edit_29ea252e-a81e-4b21-a41c-09209c780bb2.bmp" /> by geometric analysis, which has the symmetry: v=0 if β=0, and basic expression <img alt="" src="Edit_bc7a883f-312d-44fd-bcdd-00f25c92f80a.bmp" />. We show that |u| is single peak in each root-interval <img alt="" src="Edit_d7ca54c7-4866-4419-a4bd-cbb808b365af.bmp" /> of u for fixed β ∈(0,1/2]. Using the slope u<sub>t</sub>, we prove that v has opposite signs at two end-points of I<sub>j</sub>. There surely exists an inner point such that , so {|u|,|v|/β} form a local peak-valley structure, and have positive lower bound <img alt="" src="Edit_bac1a5f6-673e-49b6-892c-5adff0141376.bmp" /> in I<sub>j</sub>. Because each t must lie in some I<sub>j</sub>, then ||ξ|| > 0 is valid for any t (i.e. RH is true). Using the positivity <img alt="" src="Edit_83c3d2cf-aa7e-4aba-89f5-0eb44659918a.bmp" /> of Lagarias (1999), we show the strict monotone <img alt="" src="Edit_87eb4e9e-bc7b-43e3-b316-5dcf0efaf0d5.bmp" /> for β > β<sub>0</sub> ≥ 0 , and the peak-valley structure is equiva-lent to RH, which may be the geometric model expected by Bombieri (2000). This research follows Liuhui’s methodology: “Computing can detect the un-known and method”.
文摘An RFID (Radio-Frequency IDentification) system provides the mechanism to identify tags to readers and then to execute specific RFID-enabled applications. In those applications, secure protocols using lightweight cryptography need to be developed and the privacy of tags must be ensured. In 2010, Batina et al. proposed a privacy-preserving grouping proof protocol for RFID based on ECC (Elliptic Curve Cryptography) in public-key cryptosystem. In the next year, Lv et al. had shown that Batina et al.’s protocol was insecure against the tracking attack such that the privacy of tags did not be preserved properly. Then they proposed a revised protocol based on Batina et al.’s work. Their revised protocol was claimed to have all security properties and resisted tracking attack. But in this paper, we prove that Lv et al.’s protocol cannot work properly. Then we propose a new version protocol with some nonce to satisfy the functions of Batina et al.’s privacy-preserving grouping proof protocol. Further we try the tracing attack made by Lv et al. on our protocol and prove our protocol can resist this attack to recover the untraceability.
基金This work has been supported by the Open Research Funding from Key Laboratory of Infrared Imaging Materials and Detectors(Shanghai Institute of Technical Physics,Chinese Academy of Sciences)。
文摘Nowadays, multi-functional materials are desperately required for adapting the complex environment, which urges us to take more factors into consideration. Here, we proposed a broadband microwave absorber with multi-functionality such as optically transparent, thermal insulating and soundproof properties. Using indium tin oxide(ITO) based metamaterial, the device can achieve above 90% microwave absorption from 5.6 GHz to 23 GHz(cover X and Ku band). Moreover, with designed vacuum structure inside, the device is thermal insulating and soundproof. These multi-functional advantages give the absorber more flexibility in electromagnetic shielding and stealth application, which can be potentially applied in windows related industry.
文摘Background: Nine proteins were identified as putative profibrotic biomarkers in systemic sclerosis (SSc) and an unrelated fibrotic disease in a previously published proteomic study. As the majority of these proteins were orphans of commercially available antibodies, the nine proteins were investigated to determine whether binding peptide aptamers of the Stefin A quadruple mutant-Tracy variant (referred to as “affimers”) could be validated by enzyme linked immunosorbant assay (ELISA) to allow the quantification of these candidate biomarkers in the sera of SSc patients. Materials and Methods: Candidate biomarker peptides were analysed by high throughput affimer microarray to identify binding affimers. Two candidate biomarkers were prioritised, and binding affimers were expressed from genetically modified BL21 competent E. coli strains and purified. These affimers were used in indirect ELISA, and then sandwich ELISA formats against the candidate biomarker recombinant proteins osteonectin and pigment epi-thetlium-derived factor (PEDF). Results: 39 affimers were identified as binders for eight of the nine candidate biomarker peptides were by affimer microarray;six for osteonectin and eleven for PEDF. Two of the six and all eleven were able to recognize physiological concentrations (5 and 1 μg·ml﹣1) of osteonectin and PEDF, respectively by indirect ELISA. In sandwich ELISA format: two affimers were able to detect recombinant PEDF;however, the two affimers identified in indirect ELISA were unable to recognise recombinant osteonectin, and were thus hypothesised to bind to osteonectin at the same binding site. Discussion: SSc is currently an orphan of fully validated biomarkers, which is required for the development of stratified medicine in this field. This approach has laid the groundwork for an affimer based on multiplexed assay, to validate biomarkers in the sera of SSc patients in the future.
文摘The author presents a new approach which is used to solve an important Diophantine problem. An elementary argument is used to furnish another fully transparent proof of Fermat’s Last Theorem. This was first stated by Pierre de Fermat in the seventeenth century. It is widely regarded that no elementary proof of this theorem exists. The author provides evidence to dispel this belief.
文摘This paper introduces a conceptual framework for developing pedagogical games of mathematical proof (PGMP) designed to help non-STEM students learn mathematical reasoning in a playful manner and without “fear”. Within the constructivist learning paradigm it develops an in-class learning activity where social science students learn the concept of mathematical deduction playfully using toys to construct tables from which formal proofs of propositions are derived without calculations. A PGMP pedagogy quality assurance evaluation method based on fuzzy evaluation mappings capturing learning effectiveness, learning efficiency, and learning satisfaction is introduced. Our results from an in-class experiment show that pedagogical games of mathematical proof help non-STEM students to effectively engage with mathematical reasoning playfully. The results are consistent according to a quality assurance consistency index.
基金partially supported by the Fundamental Research Funds for the Central Universities of China under Grant No.2015JBM034the China Scholarship Council Funds under File No.201407095023
文摘How to keep cloud data intact and available to users is a problem to be solved. Authenticated skip list is an important data structure used in cloud data integrity verification. How to get the membership proof of the element in authenticated skip list efficiently is an important part of authentication. Kaouthar Blibech and Alban Gabillon proposed a head proof and a tail proof algorithms for the membership proof of elements in the authenticated skip list. However, the proposed algorithms are uncorrelated each other and need plateau function. We propose a new algorithm for computing the membership proof for elements in the authenticated skip list by using two stacks, one is for storing traversal chain of leaf node, the other is for storing authentication path for the leaf. The proposed algorithm is simple and effective without needing plateau function. It can also be applicable for other similar binary hash trees.
