In the age of smartphones, people do most of their daily work using their smartphones due to significant improvement in smartphone technology. When comparing different platforms such as Windows, iOS, Android, and Blac...In the age of smartphones, people do most of their daily work using their smartphones due to significant improvement in smartphone technology. When comparing different platforms such as Windows, iOS, Android, and Blackberry, Android has captured the highest percentage of total market share [1]. Due to this tremendous growth, cybercriminals are encouraged to penetrate various mobile marketplaces with malicious applications. Most of these applications require device information permissions aiming to collect sensitive data without user’s consent. This paper investigates each element of system information permissions and illustrates how cybercriminals can harm users’ privacy. It presents some attack scenarios using READ_PHONE_STATE permission and the risks behind it. In addition, this paper refers to possible attacks that can be performed when additional permissions are combined with READ_PHONE_STATE permission. It also discusses a proposed solution to defeat these types of attacks.展开更多
Mobile applications affect user’s privacy based on the granted application’s permissions as attackers exploit mobile application permissions in Android and other mobile operating systems. This research divides permi...Mobile applications affect user’s privacy based on the granted application’s permissions as attackers exploit mobile application permissions in Android and other mobile operating systems. This research divides permissions based on Google’s classification of dangerous permissions into three groups. The first group contains the permissions that can access user’s private data such as reading call log. The second group contains the permissions that can modify user’s data such as modifying the numbers in contacts. The third group contains the remaining permissions which can track the location, and use the microphone and other sensitive issues that can spy on the user. This research is supported by a study that was conducted on 100 participants in Saudi Arabia to show the level of users’ awareness of associated risks in mobile applications permissions. Associations among the collected data are also analyzed. This research fills the gap in user’s awareness by providing best practices in addition to developing a new mobile application to help users decide whether an application is safe to be installed and used or not. This application is called “Sparrow” and is available in Google Play Store.展开更多
Amid the increasing demand for data sharing,the need for flexible,secure,and auditable access control mechanisms has garnered significant attention in the academic community.However,blockchain-based ciphertextpolicy a...Amid the increasing demand for data sharing,the need for flexible,secure,and auditable access control mechanisms has garnered significant attention in the academic community.However,blockchain-based ciphertextpolicy attribute-based encryption(CP-ABE)schemes still face cumbersome ciphertext re-encryption and insufficient oversight when handling dynamic attribute changes and cross-chain collaboration.To address these issues,we propose a dynamic permission attribute-encryption scheme for multi-chain collaboration.This scheme incorporates a multiauthority architecture for distributed attribute management and integrates an attribute revocation and granting mechanism that eliminates the need for ciphertext re-encryption,effectively reducing both computational and communication overhead.It leverages the InterPlanetary File System(IPFS)for off-chain data storage and constructs a cross-chain regulatory framework—comprising a Hyperledger Fabric business chain and a FISCO BCOS regulatory chain—to record changes in decryption privileges and access behaviors in an auditable manner.Security analysis shows selective indistinguishability under chosen-plaintext attack(sIND-CPA)security under the decisional q-Parallel Bilinear Diffie-Hellman Exponent Assumption(q-PBDHE).In the performance and experimental evaluations,we compared the proposed scheme with several advanced schemes.The results show that,while preserving security,the proposed scheme achieves higher encryption/decryption efficiency and lower storage overhead for ciphertexts and keys.展开更多
1Legal requirements.The author(s)guarantee(s)that the manuscript will not be published elsewhere in any language without the consent of the copyright holders,that the rights of third parties will not be violated,and t...1Legal requirements.The author(s)guarantee(s)that the manuscript will not be published elsewhere in any language without the consent of the copyright holders,that the rights of third parties will not be violated,and that the publisher will not be held legally responsible should there be any claims for compensation.Authors wishing to include figures or text passages that have already been published elsewhere are required to obtain permission from the copyright holder(s)and to include evidence that such permission has been granted when submitting their papers.Any material received without such evidence will be assumed to originate from the authors.展开更多
1Legal requirements The author(s)guarantee(s)that the manuscript will not be published elsewhere in any language without the consent of the copyright holders,that the rights of third parties will not be violated,and t...1Legal requirements The author(s)guarantee(s)that the manuscript will not be published elsewhere in any language without the consent of the copyright holders,that the rights of third parties will not be violated,and that the publisher will not be held legally responsible should there be any claims for compensation.Authors wishing to include figures or text passages that have already been published elsewhere are required to obtain permission from the copyright holder(s)and to include evidence that such permission has been granted when submitting their papers.Any material received without such evidence will be assumed to originate from the authors.展开更多
China Nitrogenous Fertilizer Industry Association(CNFIA) disclosed on March 12th thatthe drafted permission conditions for the syntheticammonia will soon be submitted to theMinistry of Industry and Information Technol...China Nitrogenous Fertilizer Industry Association(CNFIA) disclosed on March 12th thatthe drafted permission conditions for the syntheticammonia will soon be submitted to theMinistry of Industry and Information Technologyof China for approval.The draftedpermissions, drawn by CFNIA, proposedprimarily the minimum capacity for new syntheticammonia project is 300 000 t/a, mean-展开更多
BACKGROUND An investigation is undertaken to assess the effects of permissive hypercapnia(PH)combined with goal-directed fluid therapy(GDFT)on postoperative recovery and psychological well-being among elderly patients...BACKGROUND An investigation is undertaken to assess the effects of permissive hypercapnia(PH)combined with goal-directed fluid therapy(GDFT)on postoperative recovery and psychological well-being among elderly patients undergoing laparoscopic surgical procedures.AIM To ascertain whether the combination of PH and GDFT improves clinical recovery indicators,reduces postoperative complications,and alleviates anxiety,depression,and inflammatory responses in this specific patient population.METHODS A total of 120 elderly patients who underwent laparoscopic surgery in our hospital from July 2023 to June 2024 were randomly allocated into two groups:A control group(n=60)and a study group(n=60).In the control group,conventional anesthesia ventilation and fluid management protocols were administered,while in the study group,PH(with intraoperative PaCO_(2) maintained between 45-55 mmHg)was combined with GDFT.Postoperative recovery indicators,including the time to first flatus,time to ambulation,and length of hospital stay,were compared between the groups.Additionally,complication rates,anxietydepression scores assessed via the Hospital Anxiety and Depression scale,and levels of inflammatory factors were analyzed to evaluate the outcomes.RESULTS When compared with the control group,the study group demonstrated significantly shorter time to first flatus[(48.3±6.2)hours vs(62.5±7.8)hours],time to ambulation[(28.4±4.2)hours vs(38.6±5.1)hours],and length of hospital stay[(5.2±1.1)days vs(7.4±1.3)days](P<0.05).A significantly lower postoperative complication rate was observed in the study group(8.3%vs 21.7%,P<0.05).Additionally,at 3 days postoperatively,significantly lower anxiety scores[(5.2±1.4)vs(7.8±1.6)]and depression scores[(4.8±1.2)vs(7.1±1.5)]were recorded in the study group compared to the control group(P<0.05);Furthermore,at 24 hours postoperatively,serum levels of interleukin-6,tumor necrosis factorα,and C-reactive protein were found to be significantly lower in the study group than in the control group(P<0.05).CONCLUSION Postoperative recovery is significantly expedited,postoperative complications are markedly reduced,anxietydepression status is substantially improved,and inflammatory response is notably diminished in elderly patients undergoing laparoscopic surgery when PH is combined with GDFT,thereby making it worthy of clinical application.展开更多
In the legal and philosophical study of torture,two major problems arise:Why is torture evil(Problem 1)?And is there a form of permissible torture(Problem 2)?The key issue in Problem 1 is demonstrating the uniqueness ...In the legal and philosophical study of torture,two major problems arise:Why is torture evil(Problem 1)?And is there a form of permissible torture(Problem 2)?The key issue in Problem 1 is demonstrating the uniqueness of the evils of torture,while Problem 2 aims to find a suitable theory to balance the“intuitive rejection”and“intuition of exceptional cases”in the ticking bomb scenario.Existing mainstream approaches have generally failed to resolve these issues.However,Matthew Kramer’s view of torture addresses both aspects of these problems.For Problem 1,Kramer adopts a perpetrator-centered viewpoint,arguing that torture undermines the moral integrity of the perpetrator.Regarding Problem 2,he suggests that the situation we face is a moral conflict in which the use of torture is morally wrong but might be the best action in a given context,granting it a weaker form of permissibility.However,in terms of the evils of torture,Kramer fails to explain its uniqueness.His theory cannot apply to all types of torture,and his perpetrator-centered argument contains logical flaws.Regarding the permissibility of torture,while Kramer’s overall approach is correct,he does not provide a reasonable explanation of the moral obligation to“forbid torture”or the prima facie surrounding it.A correct view of torture should adhere to an inmate-centered viewpoint,understanding the evils of torture in an additive manner in Problem 1,and acknowledging the existence of moral conflict in Problem 2.It should not only demonstrate that,in some situations,the use of torture may be the morally best option,but also show that the moral obligation to prohibit torture is simply outweighed under these circumstances.展开更多
Vertical Federated Learning(VFL),which draws attention because of its ability to evaluate individuals based on features spread across multiple institutions,encounters numerous privacy and security threats.Existing sol...Vertical Federated Learning(VFL),which draws attention because of its ability to evaluate individuals based on features spread across multiple institutions,encounters numerous privacy and security threats.Existing solutions often suffer from centralized architectures,and exorbitant costs.To mitigate these issues,in this paper,we propose SecureVFL,a decentralized multi-party VFL scheme designed to enhance efficiency and trustworthiness while guaranteeing privacy.SecureVFL uses a permissioned blockchain and introduces a novel consensus algorithm,Proof of Feature Sharing(PoFS),to facilitate decentralized,trustworthy,and high-throughput federated training.SecureVFL introduces a verifiable and lightweight three-party Replicated Secret Sharing(RSS)protocol for feature intersection summation among overlapping users.Furthermore,we propose a(_(2)^(4))-sharing protocol to achieve federated training in a four-party VFL setting.This protocol involves only addition operations and exhibits robustness.SecureVFL not only enables anonymous interactions among participants but also safeguards their real identities,and provides mechanisms to unmask these identities when malicious activities are performed.We illustrate the proposed mechanism through a case study on VFL across four banks.Finally,our theoretical analysis proves the security of SecureVFL.Experiments demonstrated that SecureVFL outperformed existing multi-party VFL privacy-preserving schemes,such as MP-FedXGB,in terms of both overhead and model performance.展开更多
An unauthorised version of the Chinese MMSE was used in this article by the authors without permission from the copyright owner,PAR.Necessary permission has now been retrospectively obtained from PAR.The MMSE is a cop...An unauthorised version of the Chinese MMSE was used in this article by the authors without permission from the copyright owner,PAR.Necessary permission has now been retrospectively obtained from PAR.The MMSE is a copyrighted instrument and may not be used or reproduced in whole or in part,in any form or language,or by any means without the written permission of PAR(www.parinc.com).展开更多
The editors regret that the following statements were missing in the published version for the following articles that appeared in previous issues of Data Science and Management:1.“Audiovisual speech recognition base...The editors regret that the following statements were missing in the published version for the following articles that appeared in previous issues of Data Science and Management:1.“Audiovisual speech recognition based on a deep convolutional neural network”(Data Science and Management,2024,7(1):25–34).https://doi.org/10.1016/j.dsm.2023.10.002.Ethics statement:The authors declare the Institutional Ethics Committee confirmed that no ethical review was required for this study.The authors have taken the participants’permission and consent to participate in this study.展开更多
In recent days the usage of android smartphones has increased exten-sively by end-users.There are several applications in different categories bank-ing/finance,social engineering,education,sports andfitness,and many mor...In recent days the usage of android smartphones has increased exten-sively by end-users.There are several applications in different categories bank-ing/finance,social engineering,education,sports andfitness,and many more applications.The android stack is more vulnerable compared to other mobile plat-forms like IOS,Windows,or Blackberry because of the open-source platform.In the Existing system,malware is written using vulnerable system calls to bypass signature detection important drawback is might not work with zero-day exploits and stealth malware.The attackers target the victim with various attacks like adware,backdoor,spyware,ransomware,and zero-day exploits and create threat hunts on the day-to-day basics.In the existing approach,there are various tradi-tional machine learning classifiers for building a decision support system with limitations such as low detection rate and less feature selection.The important contents taken for building model from android applications like Intent Filter,Per-mission Signature,API Calls,and System commands are taken from the manifestfile.The function parameters of various machine and deep learning classifiers like Nave Bayes,k-Nearest Neighbors(k-NN),Support Vector Machine(SVM),Ada Boost,and Multi-Layer Perceptron(MLP)are done for effective results.In our pro-posed work,we have used an unsupervised learning multilayer perceptron with multiple target labels and built a model with a better accuracy rate compared to logistic regression,and rank the best features for detection of applications and clas-sify as malicious or benign can be used as threat model by online antivirus scanners.展开更多
The minimum rolling thickness in asymmetrical rolling was analyzed compared with that in symmetrical rolling. The differential equilibrium equations on forces were established to calculate the asymmetrical rolling for...The minimum rolling thickness in asymmetrical rolling was analyzed compared with that in symmetrical rolling. The differential equilibrium equations on forces were established to calculate the asymmetrical rolling force equation by slab method. An implicit expression of the minimum rolling thickness was then derived from the rolling force equation and Hitehcock equation. The results show that permissible minimum rolling thickness of asymmetrical rolling only exists within a specific range of cross-shear ratio, which is termed the cross-shear zone proportion of the whole de- formation zone. Numerical computation was carried out to obtain a discrete solution of the minimum rolling thick- ness. Experiments were designed to investigate the influence factors on cross-shear ratio. Finally, experimental re- sults prove the correctness of the improved formula given.展开更多
文摘In the age of smartphones, people do most of their daily work using their smartphones due to significant improvement in smartphone technology. When comparing different platforms such as Windows, iOS, Android, and Blackberry, Android has captured the highest percentage of total market share [1]. Due to this tremendous growth, cybercriminals are encouraged to penetrate various mobile marketplaces with malicious applications. Most of these applications require device information permissions aiming to collect sensitive data without user’s consent. This paper investigates each element of system information permissions and illustrates how cybercriminals can harm users’ privacy. It presents some attack scenarios using READ_PHONE_STATE permission and the risks behind it. In addition, this paper refers to possible attacks that can be performed when additional permissions are combined with READ_PHONE_STATE permission. It also discusses a proposed solution to defeat these types of attacks.
文摘Mobile applications affect user’s privacy based on the granted application’s permissions as attackers exploit mobile application permissions in Android and other mobile operating systems. This research divides permissions based on Google’s classification of dangerous permissions into three groups. The first group contains the permissions that can access user’s private data such as reading call log. The second group contains the permissions that can modify user’s data such as modifying the numbers in contacts. The third group contains the remaining permissions which can track the location, and use the microphone and other sensitive issues that can spy on the user. This research is supported by a study that was conducted on 100 participants in Saudi Arabia to show the level of users’ awareness of associated risks in mobile applications permissions. Associations among the collected data are also analyzed. This research fills the gap in user’s awareness by providing best practices in addition to developing a new mobile application to help users decide whether an application is safe to be installed and used or not. This application is called “Sparrow” and is available in Google Play Store.
文摘Amid the increasing demand for data sharing,the need for flexible,secure,and auditable access control mechanisms has garnered significant attention in the academic community.However,blockchain-based ciphertextpolicy attribute-based encryption(CP-ABE)schemes still face cumbersome ciphertext re-encryption and insufficient oversight when handling dynamic attribute changes and cross-chain collaboration.To address these issues,we propose a dynamic permission attribute-encryption scheme for multi-chain collaboration.This scheme incorporates a multiauthority architecture for distributed attribute management and integrates an attribute revocation and granting mechanism that eliminates the need for ciphertext re-encryption,effectively reducing both computational and communication overhead.It leverages the InterPlanetary File System(IPFS)for off-chain data storage and constructs a cross-chain regulatory framework—comprising a Hyperledger Fabric business chain and a FISCO BCOS regulatory chain—to record changes in decryption privileges and access behaviors in an auditable manner.Security analysis shows selective indistinguishability under chosen-plaintext attack(sIND-CPA)security under the decisional q-Parallel Bilinear Diffie-Hellman Exponent Assumption(q-PBDHE).In the performance and experimental evaluations,we compared the proposed scheme with several advanced schemes.The results show that,while preserving security,the proposed scheme achieves higher encryption/decryption efficiency and lower storage overhead for ciphertexts and keys.
文摘1Legal requirements.The author(s)guarantee(s)that the manuscript will not be published elsewhere in any language without the consent of the copyright holders,that the rights of third parties will not be violated,and that the publisher will not be held legally responsible should there be any claims for compensation.Authors wishing to include figures or text passages that have already been published elsewhere are required to obtain permission from the copyright holder(s)and to include evidence that such permission has been granted when submitting their papers.Any material received without such evidence will be assumed to originate from the authors.
文摘1Legal requirements The author(s)guarantee(s)that the manuscript will not be published elsewhere in any language without the consent of the copyright holders,that the rights of third parties will not be violated,and that the publisher will not be held legally responsible should there be any claims for compensation.Authors wishing to include figures or text passages that have already been published elsewhere are required to obtain permission from the copyright holder(s)and to include evidence that such permission has been granted when submitting their papers.Any material received without such evidence will be assumed to originate from the authors.
文摘China Nitrogenous Fertilizer Industry Association(CNFIA) disclosed on March 12th thatthe drafted permission conditions for the syntheticammonia will soon be submitted to theMinistry of Industry and Information Technologyof China for approval.The draftedpermissions, drawn by CFNIA, proposedprimarily the minimum capacity for new syntheticammonia project is 300 000 t/a, mean-
基金Supported by the 2024 Hebei Medical Science Research Project,No.20241638Key Research and Development Program of Zhangjiakou City,No.2311041D.
文摘BACKGROUND An investigation is undertaken to assess the effects of permissive hypercapnia(PH)combined with goal-directed fluid therapy(GDFT)on postoperative recovery and psychological well-being among elderly patients undergoing laparoscopic surgical procedures.AIM To ascertain whether the combination of PH and GDFT improves clinical recovery indicators,reduces postoperative complications,and alleviates anxiety,depression,and inflammatory responses in this specific patient population.METHODS A total of 120 elderly patients who underwent laparoscopic surgery in our hospital from July 2023 to June 2024 were randomly allocated into two groups:A control group(n=60)and a study group(n=60).In the control group,conventional anesthesia ventilation and fluid management protocols were administered,while in the study group,PH(with intraoperative PaCO_(2) maintained between 45-55 mmHg)was combined with GDFT.Postoperative recovery indicators,including the time to first flatus,time to ambulation,and length of hospital stay,were compared between the groups.Additionally,complication rates,anxietydepression scores assessed via the Hospital Anxiety and Depression scale,and levels of inflammatory factors were analyzed to evaluate the outcomes.RESULTS When compared with the control group,the study group demonstrated significantly shorter time to first flatus[(48.3±6.2)hours vs(62.5±7.8)hours],time to ambulation[(28.4±4.2)hours vs(38.6±5.1)hours],and length of hospital stay[(5.2±1.1)days vs(7.4±1.3)days](P<0.05).A significantly lower postoperative complication rate was observed in the study group(8.3%vs 21.7%,P<0.05).Additionally,at 3 days postoperatively,significantly lower anxiety scores[(5.2±1.4)vs(7.8±1.6)]and depression scores[(4.8±1.2)vs(7.1±1.5)]were recorded in the study group compared to the control group(P<0.05);Furthermore,at 24 hours postoperatively,serum levels of interleukin-6,tumor necrosis factorα,and C-reactive protein were found to be significantly lower in the study group than in the control group(P<0.05).CONCLUSION Postoperative recovery is significantly expedited,postoperative complications are markedly reduced,anxietydepression status is substantially improved,and inflammatory response is notably diminished in elderly patients undergoing laparoscopic surgery when PH is combined with GDFT,thereby making it worthy of clinical application.
基金This text represents a periodic outcome of the Beijing Social Science Fund Youth Project(Project Approval Number 22FXC018).
文摘In the legal and philosophical study of torture,two major problems arise:Why is torture evil(Problem 1)?And is there a form of permissible torture(Problem 2)?The key issue in Problem 1 is demonstrating the uniqueness of the evils of torture,while Problem 2 aims to find a suitable theory to balance the“intuitive rejection”and“intuition of exceptional cases”in the ticking bomb scenario.Existing mainstream approaches have generally failed to resolve these issues.However,Matthew Kramer’s view of torture addresses both aspects of these problems.For Problem 1,Kramer adopts a perpetrator-centered viewpoint,arguing that torture undermines the moral integrity of the perpetrator.Regarding Problem 2,he suggests that the situation we face is a moral conflict in which the use of torture is morally wrong but might be the best action in a given context,granting it a weaker form of permissibility.However,in terms of the evils of torture,Kramer fails to explain its uniqueness.His theory cannot apply to all types of torture,and his perpetrator-centered argument contains logical flaws.Regarding the permissibility of torture,while Kramer’s overall approach is correct,he does not provide a reasonable explanation of the moral obligation to“forbid torture”or the prima facie surrounding it.A correct view of torture should adhere to an inmate-centered viewpoint,understanding the evils of torture in an additive manner in Problem 1,and acknowledging the existence of moral conflict in Problem 2.It should not only demonstrate that,in some situations,the use of torture may be the morally best option,but also show that the moral obligation to prohibit torture is simply outweighed under these circumstances.
基金supported by Open Research Projects of Zhejiang Lab(No.2022QA0AB02)Natural Science Foundation of Sichuan Province(2022NSFSC0913)Sichuan Province Selected Funding for Postdoctoral Research Projects(TB2022032).
文摘Vertical Federated Learning(VFL),which draws attention because of its ability to evaluate individuals based on features spread across multiple institutions,encounters numerous privacy and security threats.Existing solutions often suffer from centralized architectures,and exorbitant costs.To mitigate these issues,in this paper,we propose SecureVFL,a decentralized multi-party VFL scheme designed to enhance efficiency and trustworthiness while guaranteeing privacy.SecureVFL uses a permissioned blockchain and introduces a novel consensus algorithm,Proof of Feature Sharing(PoFS),to facilitate decentralized,trustworthy,and high-throughput federated training.SecureVFL introduces a verifiable and lightweight three-party Replicated Secret Sharing(RSS)protocol for feature intersection summation among overlapping users.Furthermore,we propose a(_(2)^(4))-sharing protocol to achieve federated training in a four-party VFL setting.This protocol involves only addition operations and exhibits robustness.SecureVFL not only enables anonymous interactions among participants but also safeguards their real identities,and provides mechanisms to unmask these identities when malicious activities are performed.We illustrate the proposed mechanism through a case study on VFL across four banks.Finally,our theoretical analysis proves the security of SecureVFL.Experiments demonstrated that SecureVFL outperformed existing multi-party VFL privacy-preserving schemes,such as MP-FedXGB,in terms of both overhead and model performance.
文摘An unauthorised version of the Chinese MMSE was used in this article by the authors without permission from the copyright owner,PAR.Necessary permission has now been retrospectively obtained from PAR.The MMSE is a copyrighted instrument and may not be used or reproduced in whole or in part,in any form or language,or by any means without the written permission of PAR(www.parinc.com).
文摘The editors regret that the following statements were missing in the published version for the following articles that appeared in previous issues of Data Science and Management:1.“Audiovisual speech recognition based on a deep convolutional neural network”(Data Science and Management,2024,7(1):25–34).https://doi.org/10.1016/j.dsm.2023.10.002.Ethics statement:The authors declare the Institutional Ethics Committee confirmed that no ethical review was required for this study.The authors have taken the participants’permission and consent to participate in this study.
文摘In recent days the usage of android smartphones has increased exten-sively by end-users.There are several applications in different categories bank-ing/finance,social engineering,education,sports andfitness,and many more applications.The android stack is more vulnerable compared to other mobile plat-forms like IOS,Windows,or Blackberry because of the open-source platform.In the Existing system,malware is written using vulnerable system calls to bypass signature detection important drawback is might not work with zero-day exploits and stealth malware.The attackers target the victim with various attacks like adware,backdoor,spyware,ransomware,and zero-day exploits and create threat hunts on the day-to-day basics.In the existing approach,there are various tradi-tional machine learning classifiers for building a decision support system with limitations such as low detection rate and less feature selection.The important contents taken for building model from android applications like Intent Filter,Per-mission Signature,API Calls,and System commands are taken from the manifestfile.The function parameters of various machine and deep learning classifiers like Nave Bayes,k-Nearest Neighbors(k-NN),Support Vector Machine(SVM),Ada Boost,and Multi-Layer Perceptron(MLP)are done for effective results.In our pro-posed work,we have used an unsupervised learning multilayer perceptron with multiple target labels and built a model with a better accuracy rate compared to logistic regression,and rank the best features for detection of applications and clas-sify as malicious or benign can be used as threat model by online antivirus scanners.
基金Sponsored by National Natural Science Foundation of China(50974039)
文摘The minimum rolling thickness in asymmetrical rolling was analyzed compared with that in symmetrical rolling. The differential equilibrium equations on forces were established to calculate the asymmetrical rolling force equation by slab method. An implicit expression of the minimum rolling thickness was then derived from the rolling force equation and Hitehcock equation. The results show that permissible minimum rolling thickness of asymmetrical rolling only exists within a specific range of cross-shear ratio, which is termed the cross-shear zone proportion of the whole de- formation zone. Numerical computation was carried out to obtain a discrete solution of the minimum rolling thick- ness. Experiments were designed to investigate the influence factors on cross-shear ratio. Finally, experimental re- sults prove the correctness of the improved formula given.
