Purpose:This study aimed to explore whether the attitudes of nursing students toward the use of mobile learning are positive or negative and to identify the factors influencing their attitudes by reviewing the literat...Purpose:This study aimed to explore whether the attitudes of nursing students toward the use of mobile learning are positive or negative and to identify the factors influencing their attitudes by reviewing the literature.Methods:Electronic search of six databases,including PubMed,the Cumulative Index of Nursing and Allied Health Literature,ProQuest,Web of Science,EMBASE,and Cochrane Library,was conducted,and relevant references within articles were manually searched.Retrieval time was from inception to October 21,2020.The literature review was conducted in accordance with the PRISMA guidelines and the integrative review method.The Mixed Method Appraisal Tool(MMAT)was used for quality assessment.Results:A total of 316 articles were identified,and 18 English-language studies were finally included by reviewing titles,abstracts,and full text.Six quantitative,five qualitative,and seven mixed-method articles related to nursing students’attitudes toward the use of mobile learning were identified.The results showed that most nursing students had positive attitudes toward mobile learning.Although students expressed strong intentions for mobile learning,the actual usage rate in practical settings was low.Several advantageous factors included usefulness,convenience,and ease of use,whereas disadvantageous factors included hardware facility,updated content,and software stability.Conclusion:Most nursing students have positive attitudes and willingness to mobile learning,but the actual use rate remains low.Advantageous and disadvantageous factors coexist.Further studies are needed to assess how mobile learning improves nursing students’clinical knowledge and improves patient care.展开更多
The space-air-ground integrated network(SAGIN)combines the superiority of the satellite,aerial,and ground communications,which is envisioned to provide high-precision positioning ability as well as seamless connectivi...The space-air-ground integrated network(SAGIN)combines the superiority of the satellite,aerial,and ground communications,which is envisioned to provide high-precision positioning ability as well as seamless connectivity in the 5G and Beyond 5G(B5G)systems.In this paper,we propose a three-dimensional SAGIN localization scheme for ground agents utilizing multi-source information from satellites,base stations and unmanned aerial vehicles(UAVs).Based on the designed scheme,we derive the positioning performance bound and establish a distributed maximum likelihood algorithm to jointly estimate the positions and clock offsets of ground agents.Simulation results demonstrate the validity of the SAGIN localization scheme and reveal the effects of the number of satellites,the number of base stations,the number of UAVs and clock noise on positioning performance.展开更多
Ultra-Wide Bandwidth(UWB)localization based on time of arrival(TOA)and angle of arrival(AOA)has attracted increasing interest owing to its high accuracy and low cost.However,existing localization methods often fail to...Ultra-Wide Bandwidth(UWB)localization based on time of arrival(TOA)and angle of arrival(AOA)has attracted increasing interest owing to its high accuracy and low cost.However,existing localization methods often fail to achieve satisfactory accuracy in realistic environments due to multipath effects and non-line-of-sight(NLOS)propagation.In this paper,we propose a passive anchor assisted localization(PAAL)scheme,where the active anchor obtains TOA/AOA measurements to the agent while the passive anchors capture the signals from the active anchor and agent.The proposed method fully exploits the time-difference-of-arrival(TDOA)information from the measurements at the passive anchors to complement single-anchor joint TOA/AOA localization.The performance limits of the PAAL system are derived as a benchmark via the information inequality.Moreover,we implement the PAAL system on a low-cost UWB platform,which can achieve 20 cm localization accuracy in NLOS environments.展开更多
Background Patients with major depressive disorder(MDD)may have an abnormal peripheral body temperature rhythm,but its relationship with suicidal risk and the response to treatment with antidepressants remain unknown....Background Patients with major depressive disorder(MDD)may have an abnormal peripheral body temperature rhythm,but its relationship with suicidal risk and the response to treatment with antidepressants remain unknown.Aims This study aimed to investigate the feature of peripheral body temperature in patients with MDD and its relationship with suicide risk before and after treatment with antidepressants.Methods This is a prospective case-control study.Patients diagnosed as MDD were enrolled into MDD group.Healthy subjects who matched in terms of gender,age and body mass index were enrolled into normal control(NC)group.The 24-hour peripheral body temperatures were monitored by TM’Holter the next day after assessment.Patients with MDD were re-assessed after a 2-week treatment with antidepressants.All temperature data were fitted into cosine curves by Python.Result There were 41 patients with MDD,and 21 NC participants enrolled and completed the baseline assessments before the treatment.Patients with MDD were further divided into subgroup of with suicide risk or without suicide risk.In patients with MDD,the mesor of peripheral body temperature rhythm was higher in both patients with(36.17(0.30))and without suicide risk(36.22(0.27))than the mesor in NC participants before treatment(35.84(0.38),Z=11.82,p=0.003,Kruskal-Wallis test).The phase-delay of temperature before treatment was greater in patients with MDD with suicidal risk(4.71(1.68))in comparison with those without suicidal risk(3.05(2.19))and NC participants(3.19(1.82),Z=9.68,p=0.008,Kruskal-Wallis test).Moreover,phase-delay of temperature was associated with suicide risk in patients with MDD before treatment(OR=1.046,95%CI:1.009 to 1.085,p=0.015,unadjusted;OR=1.080,95%CI:1.020 to 1.144,p=0.009,adjusted by age and sex).Conclusion Patients with MDD might have abnormal peripheral body temperature.The abnormal phase-delay of peripheral body temperature may indicate suicide risk in patients with MDD,depending on validation in large-scale cohorts.展开更多
Cloud data sharing service,which allows a group of people to access and modify the shared data,is one of the most popular and efficient working styles in enterprises.Recently,there is an uprising trend that enterprise...Cloud data sharing service,which allows a group of people to access and modify the shared data,is one of the most popular and efficient working styles in enterprises.Recently,there is an uprising trend that enterprises tend to move their IT service from local to cloud to ease the management and reduce the cost.Under the new cloud environment,the cloud users require the data integrity verification to inspect the data service at the cloud side.Several recent studies have focused on this application scenario.In these studies,each user within a group is required to sign a data block created or modified by him.While a user is revoked,all the data previously signed by him should be resigned.In the existing research,the resigning process is dependent on the revoked user.However,cloud users are autonomous.They may exit the system at any time without notifying the system admin and even are revoked due to misbehaviors.As the developers in the cloud-based software development platform,they are voluntary and not strictly controlled by the system.Due to this feature,cloud users may not always follow the cloud service protocol.They may not participate in generating the resigning key and may even expose their secret keys after being revoked.If the signature is not resigned in time,the subsequent verification will be affected.And if the secret key is exposed,the shared data will be maliciously modified by the attacker who grasps the key.Therefore,forcing a revoked user to participate in the revocation process will lead to efficiency and security problems.As a result,designing a practical and efficient integrity verification scheme that supports this scenario is highly desirable.In this paper,we identify this challenging problem as the asynchronous revocation,in which the revocation operations(i.e.,re-signing key generation and resigning process)and the user's revocation are asynchronous.All the revocation operations must be able to be performed without the participation of the revoked user.Even more ambitiously,the revocation process should not rely on any special entity,such as the data owner or a trusted agency.To address this problem,we propose a novel public data integrity verification mechanism in which the data blocks signed by the revoked user will be resigned by another valid user.From the perspectives of security and practicality,the revoked user does not participate in the resigning process and the re-signing key generation.Our scheme allows anyone in the cloud computing system to act as the verifier to publicly and efficiently verify the integrity of the shared data using Homomorphic Verifiable Tags(HVTs).Moreover,the proposed scheme resists the collusion attack between the cloud server and the malicious revoked users.The numerical analysis and experimental results further validate the high efficiency and scalability of the proposed scheme.The experimental results manifest that re-signing 10,000 data blocks only takes 3.815 s and a user can finish the verification in 300 ms with a 99% error detection probability.展开更多
文摘Purpose:This study aimed to explore whether the attitudes of nursing students toward the use of mobile learning are positive or negative and to identify the factors influencing their attitudes by reviewing the literature.Methods:Electronic search of six databases,including PubMed,the Cumulative Index of Nursing and Allied Health Literature,ProQuest,Web of Science,EMBASE,and Cochrane Library,was conducted,and relevant references within articles were manually searched.Retrieval time was from inception to October 21,2020.The literature review was conducted in accordance with the PRISMA guidelines and the integrative review method.The Mixed Method Appraisal Tool(MMAT)was used for quality assessment.Results:A total of 316 articles were identified,and 18 English-language studies were finally included by reviewing titles,abstracts,and full text.Six quantitative,five qualitative,and seven mixed-method articles related to nursing students’attitudes toward the use of mobile learning were identified.The results showed that most nursing students had positive attitudes toward mobile learning.Although students expressed strong intentions for mobile learning,the actual usage rate in practical settings was low.Several advantageous factors included usefulness,convenience,and ease of use,whereas disadvantageous factors included hardware facility,updated content,and software stability.Conclusion:Most nursing students have positive attitudes and willingness to mobile learning,but the actual use rate remains low.Advantageous and disadvantageous factors coexist.Further studies are needed to assess how mobile learning improves nursing students’clinical knowledge and improves patient care.
文摘The space-air-ground integrated network(SAGIN)combines the superiority of the satellite,aerial,and ground communications,which is envisioned to provide high-precision positioning ability as well as seamless connectivity in the 5G and Beyond 5G(B5G)systems.In this paper,we propose a three-dimensional SAGIN localization scheme for ground agents utilizing multi-source information from satellites,base stations and unmanned aerial vehicles(UAVs).Based on the designed scheme,we derive the positioning performance bound and establish a distributed maximum likelihood algorithm to jointly estimate the positions and clock offsets of ground agents.Simulation results demonstrate the validity of the SAGIN localization scheme and reveal the effects of the number of satellites,the number of base stations,the number of UAVs and clock noise on positioning performance.
文摘Ultra-Wide Bandwidth(UWB)localization based on time of arrival(TOA)and angle of arrival(AOA)has attracted increasing interest owing to its high accuracy and low cost.However,existing localization methods often fail to achieve satisfactory accuracy in realistic environments due to multipath effects and non-line-of-sight(NLOS)propagation.In this paper,we propose a passive anchor assisted localization(PAAL)scheme,where the active anchor obtains TOA/AOA measurements to the agent while the passive anchors capture the signals from the active anchor and agent.The proposed method fully exploits the time-difference-of-arrival(TDOA)information from the measurements at the passive anchors to complement single-anchor joint TOA/AOA localization.The performance limits of the PAAL system are derived as a benchmark via the information inequality.Moreover,we implement the PAAL system on a low-cost UWB platform,which can achieve 20 cm localization accuracy in NLOS environments.
基金This work was supported by National Natural Science Foundation of China(81720108012,81571034)Fundamental Research Funds for the Central Universities(22120180112).
文摘Background Patients with major depressive disorder(MDD)may have an abnormal peripheral body temperature rhythm,but its relationship with suicidal risk and the response to treatment with antidepressants remain unknown.Aims This study aimed to investigate the feature of peripheral body temperature in patients with MDD and its relationship with suicide risk before and after treatment with antidepressants.Methods This is a prospective case-control study.Patients diagnosed as MDD were enrolled into MDD group.Healthy subjects who matched in terms of gender,age and body mass index were enrolled into normal control(NC)group.The 24-hour peripheral body temperatures were monitored by TM’Holter the next day after assessment.Patients with MDD were re-assessed after a 2-week treatment with antidepressants.All temperature data were fitted into cosine curves by Python.Result There were 41 patients with MDD,and 21 NC participants enrolled and completed the baseline assessments before the treatment.Patients with MDD were further divided into subgroup of with suicide risk or without suicide risk.In patients with MDD,the mesor of peripheral body temperature rhythm was higher in both patients with(36.17(0.30))and without suicide risk(36.22(0.27))than the mesor in NC participants before treatment(35.84(0.38),Z=11.82,p=0.003,Kruskal-Wallis test).The phase-delay of temperature before treatment was greater in patients with MDD with suicidal risk(4.71(1.68))in comparison with those without suicidal risk(3.05(2.19))and NC participants(3.19(1.82),Z=9.68,p=0.008,Kruskal-Wallis test).Moreover,phase-delay of temperature was associated with suicide risk in patients with MDD before treatment(OR=1.046,95%CI:1.009 to 1.085,p=0.015,unadjusted;OR=1.080,95%CI:1.020 to 1.144,p=0.009,adjusted by age and sex).Conclusion Patients with MDD might have abnormal peripheral body temperature.The abnormal phase-delay of peripheral body temperature may indicate suicide risk in patients with MDD,depending on validation in large-scale cohorts.
基金partially supported by National Key Research and Development Project No.2020YFC1522602National Natural Science Foundation of China Nos.62072349,U1811263,61572378+5 种基金Technological Innovation Major Program of Hubei Province No.2019AAA072Tarim University President Fund Doctoral Foundation Research Project No.19/1117596Xinjiang Regional Innovation Guidance Project No.2017DB004Basic and Advanced Research Projects of CSTC No.cstc2019jcyj-zdxm0102Chongqing Science and Technology Innovation Leading Talent Support Program No.CSTCCXLJRC201908Science and Technology Research Program of Chongqing Municipal Education Commission No.KJZD-K201900605.
文摘Cloud data sharing service,which allows a group of people to access and modify the shared data,is one of the most popular and efficient working styles in enterprises.Recently,there is an uprising trend that enterprises tend to move their IT service from local to cloud to ease the management and reduce the cost.Under the new cloud environment,the cloud users require the data integrity verification to inspect the data service at the cloud side.Several recent studies have focused on this application scenario.In these studies,each user within a group is required to sign a data block created or modified by him.While a user is revoked,all the data previously signed by him should be resigned.In the existing research,the resigning process is dependent on the revoked user.However,cloud users are autonomous.They may exit the system at any time without notifying the system admin and even are revoked due to misbehaviors.As the developers in the cloud-based software development platform,they are voluntary and not strictly controlled by the system.Due to this feature,cloud users may not always follow the cloud service protocol.They may not participate in generating the resigning key and may even expose their secret keys after being revoked.If the signature is not resigned in time,the subsequent verification will be affected.And if the secret key is exposed,the shared data will be maliciously modified by the attacker who grasps the key.Therefore,forcing a revoked user to participate in the revocation process will lead to efficiency and security problems.As a result,designing a practical and efficient integrity verification scheme that supports this scenario is highly desirable.In this paper,we identify this challenging problem as the asynchronous revocation,in which the revocation operations(i.e.,re-signing key generation and resigning process)and the user's revocation are asynchronous.All the revocation operations must be able to be performed without the participation of the revoked user.Even more ambitiously,the revocation process should not rely on any special entity,such as the data owner or a trusted agency.To address this problem,we propose a novel public data integrity verification mechanism in which the data blocks signed by the revoked user will be resigned by another valid user.From the perspectives of security and practicality,the revoked user does not participate in the resigning process and the re-signing key generation.Our scheme allows anyone in the cloud computing system to act as the verifier to publicly and efficiently verify the integrity of the shared data using Homomorphic Verifiable Tags(HVTs).Moreover,the proposed scheme resists the collusion attack between the cloud server and the malicious revoked users.The numerical analysis and experimental results further validate the high efficiency and scalability of the proposed scheme.The experimental results manifest that re-signing 10,000 data blocks only takes 3.815 s and a user can finish the verification in 300 ms with a 99% error detection probability.
