Objective:To explore the effect of nursing intervention based on Caprini risk assessment scale for venous thromboembolism(VTE)in perioperative patients with liver cancer.Methods:A total of 128 hepatocellular cancer(HC...Objective:To explore the effect of nursing intervention based on Caprini risk assessment scale for venous thromboembolism(VTE)in perioperative patients with liver cancer.Methods:A total of 128 hepatocellular cancer(HCC)patients who were hospitalized in our department from January 2021 to March 2022 and met the research criteria were selected.According to odd and even numbers in the order of inclusion,64 cases were divided into two groups:a control group and an observation group.The control group received routine nursing intervention during perioperative period,while the observation group received nursing intervention based on Caprini risk assessment scale for VTE.The incidence of VTE and complications were compared between the two groups.Results:The incidence of VTE and postoperative complications in the observation group were lower than those in the control group(P<0.05).Conclusion:Nursing intervention based on Caprini risk assessment scale for VTE can reduce the incidence of perioperative deep vein thrombosis and complications in patients with liver cancer;thus,it is worthy of clinical application.展开更多
Amplitudes have been found to be a function of incident angle and offset. Hence data required to test for amplitude variation with angle or offset needs to have its amplitudes for all offsets preserved and not stacked...Amplitudes have been found to be a function of incident angle and offset. Hence data required to test for amplitude variation with angle or offset needs to have its amplitudes for all offsets preserved and not stacked. Amplitude Variation with Offset (AVO)/Amplitude Variation with Angle (AVA) is necessary to account for information in the offset/angle parameter (mode converted S-wave and P-wave velocities). Since amplitudes are a function of the converted S- and P-waves, it is important to investigate the dependence of amplitudes on the elastic (P- and S-waves) parameters from the seismic data. By modelling these effects for different reservoir fluids via fluid substitution, various AVO geobody classes present along the well and in the entire seismic cube can be observed. AVO analysis was performed on one test well (Well_1) and 3D pre-stack angle gathers from the Tano Basin. The analysis involves creating a synthetic model to infer the effect of offset scaling techniques on amplitude responses in the Tano basin as compared to the effect of unscaled seismic data. The spectral balance process was performed to match the amplitude spectra of all angle stacks to that of the mid (26°) stack on the test lines. The process had an effect primarily on the far (34° - 40°) stacks. The frequency content of these stacks slightly increased to match that of the near and mid stacks. In offset scaling process, the root mean square (RMS) amplitude comparison between the synthetic and seismic suggests that the amplitude of the far traces should be reduced relative to the nears by up to 16%. However, the exact scaler values depend on the time window considered. This suggests that the amplitude scaling with offset delivered from seismic processing is only approximately correct and needs to be checked with well synthetics and adjusted accordingly prior to use for AVO studies. The AVO attribute volumes generated were better at resolving anomalies on spectrally balanced and offset scaled data than data delivered from conventional processing. A typical class II AVO anomaly is seen along the test well from the cross-plot analysis and AVO attribute cube which indicates an oil filled reservoir.展开更多
Timely detection of dynamical complexity changes in natural and man-made systems has deep scientific and practical meanings. We introduce a complexity measure for time series: the base-scale entropy. The definition d...Timely detection of dynamical complexity changes in natural and man-made systems has deep scientific and practical meanings. We introduce a complexity measure for time series: the base-scale entropy. The definition directly applies to arbitrary real-word data. We illustrate our method on a practical speech signal and in a theoretical chaotic system. The results show that the simple and easily calculated measure of base-scale entropy can be effectively used to detect qualitative and quantitative dynamical changes.展开更多
BACKGROUND: Convalescence is an important stage of stroke treatment. A lot of patients have somatic and mental disorders at various degrees. The primary standard can only reflect partial conditions of somatic disorder...BACKGROUND: Convalescence is an important stage of stroke treatment. A lot of patients have somatic and mental disorders at various degrees. The primary standard can only reflect partial conditions of somatic disorder; in addition, multiple dimensions of patients at the phase of stroke convalescence are further observed by using a lot of standards, such as signs and symptoms of traditional Chinese medicine, daily activity and psychological status. OBJECTIVE: To analyze the outcome assessments of the cases of stroke convalescence measured with different criteria consisting of various dimensions by a cross-sectional investigation of the condition of stroke convalescent patients. DESIGN: Scale evaluation. SETTING: Departments of Clinical Epidemiology Exploratory Development and Neurology, the Second Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine; National Center for Training of Design, Measurement and Evaluation in Clinical Research,Guangzhou University of Traditional Chinese Medicine. PARTICIPANTS: A total of 194 stroke convalescent patients treated in the Second Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine from July 26, 2000 to February 28, 2001 were taken as subjects of the study. There were 126 males and 68 females aged from 40 to 89 years, and the illness course ranged from 14 to 181 days. All patients met diagnosis-treatment criteria of stroke (the second version)[DTCS(V2.0)] and various kinds of diagnostic points of cerebrovascular diseases; moreover, all patients provided confirmed consents. METHODS: They were assessed by assessment methods including the following assessment instruments: DTCS(V2.0), self-designed scale of traditional Chinese medicine (TCM) symptoms (28 symptoms and physical signs were scored as 0, 1, 2 marks from none to severity), modified Edinburgh-Scandinavia stroke scale (a total of 45 marks, 0 to 15 marks as mild defect, 16 to 30 as moderate defect, 31 to 45 as severe defect), modified Barthel activities of daily life (ADL) index (a total of 100 marks, less than 60 marks as unable self-care), vitality and mental health (subscales derived from Health Survey Questionnaire, SF-36). The collected data from scales and inter-scale correlation were processed by the statistic methods mainly including descriptive analysis, Spearmen correlation analysis, factor analysis, etc. MAIN OUTCOME MEASURES: ① Average scores of scales and criteria; ② correlation between modified Edinburgh-Scandinavia stroke scale and other scales. RESULTS: All of the patients completed the assessment, and analyzed in the final analysis. ① The average scores of the scales and criteria: The average scores of DTCS(V2.0), self-designed scale of TCM symptoms, modified Edinburgh-Scandinavia stroke scale, modified Barthel ADL index, vitality and mental health scales were 6.51±6.29, 13.73±6.97, 7.56±7.35, 63.58±23.68, 52.79±23.32 and 62.83±22.75 respectively. ② Correlation between modified Edinburgh-Scandinavia stroke scale and other scales: The Spearman correlation coefficients (R ’) of modified Edinburgh-Scandinavia stroke scale with diagnosis-treatment criteria of stroke, scales of TCM symptoms, modified Barthel ADL index, vitality scale and mental health scale were 20.885, 0.302, -0.824, -0.294 and -0.258 respectively. CONCLUSION: The modified Edinburgh-Scandinavia stroke scale and DTCS(V2.0) shared the same assessment dimension, so they can be mutually alternated in some clinical practices. Discrepancy in measurements of health status was gained due to the diverse dimensions applied in outcome assessments. It is necessary to build up a multi-dimensional assessment criteria system, such as signs and symptoms, daily activities and psychological status, for assessing the stroke convalescent cases in a more comprehensive scope and reflecting the efficacy of TCM treatment scientifically.展开更多
The closure of a turbulence field is a longstanding fundamental problem, while most closure models are introduced in spectral space. Inspired by Chou's quasi-normal closure method in spectral space, we propose an ana...The closure of a turbulence field is a longstanding fundamental problem, while most closure models are introduced in spectral space. Inspired by Chou's quasi-normal closure method in spectral space, we propose an analytical closure model for isotropic turbulence based on the extended scale similarity theory of the velocity structure function in physical space. The assumptions and certain approximations are justified with direct numerical simulation. The asymptotic scaling properties are reproduced by this new closure method, in comparison to the classical Batchelor model.展开更多
An approach based on multi-scale chirplet sparse signal decomposition is proposed to separate the multi-component polynomial phase signals,and estimate their instantaneous frequencies.In this paper,we have generated a...An approach based on multi-scale chirplet sparse signal decomposition is proposed to separate the multi-component polynomial phase signals,and estimate their instantaneous frequencies.In this paper,we have generated a family of multi-scale chirplet functions which provide good local correlations of chirps over shorter time interval.At every decomposition stage,we build the so-called family of chirplets and our idea is to use a structured algorithm which exploits information in the family to chain chirplets together adaptively as to form the polynomial phase signal component whose correlation with the current residue signal is largest.Simultaneously,the polynomial instantaneous frequency is estimated by connecting the linear frequency of the chirplet functions adopted in the current separation.Simulation experiment demonstrated that this method can separate the components of the multi-component polynomial phase signals effectively even in the low signal-to-noise ratio condition,and estimate its instantaneous frequency accurately.展开更多
Successful modeling and/or design of engineering systems often requires one to address the impact of multiple "design variables" on the prescribed outcome.There are often multiple,competing objectives based on which...Successful modeling and/or design of engineering systems often requires one to address the impact of multiple "design variables" on the prescribed outcome.There are often multiple,competing objectives based on which we assess the outcome of optimization.Since accurate,high fidelity models are typically time consuming and computationally expensive,comprehensive evaluations can be conducted only if an efficient framework is available.Furthermore,informed decisions of the model/hardware's overall performance rely on an adequate understanding of the global,not local,sensitivity of the individual design variables on the objectives.The surrogate-based approach,which involves approximating the objectives as continuous functions of design variables from limited data,offers a rational framework to reduce the number of important input variables,i.e.,the dimension of a design or modeling space.In this paper,we review the fundamental issues that arise in surrogate-based analysis and optimization,highlighting concepts,methods,techniques,as well as modeling implications for mechanics problems.To aid the discussions of the issues involved,we summarize recent efforts in investigating cryogenic cavitating flows,active flow control based on dielectric barrier discharge concepts,and lithium(Li)-ion batteries.It is also stressed that many multi-scale mechanics problems can naturally benefit from the surrogate approach for "scale bridging."展开更多
Many real-world networks are found to be scale-free. However, graph partition technology, as a technology capable of parallel computing, performs poorly when scale-free graphs are provided. The reason for this is that...Many real-world networks are found to be scale-free. However, graph partition technology, as a technology capable of parallel computing, performs poorly when scale-free graphs are provided. The reason for this is that traditional partitioning algorithms are designed for random networks and regular networks, rather than for scale-free networks. Multilevel graph-partitioning algorithms are currently considered to be the state of the art and are used extensively. In this paper, we analyse the reasons why traditional multilevel graph-partitioning algorithms perform poorly and present a new multilevel graph-partitioning paradigm, top down partitioning, which derives its name from the comparison with the traditional bottom-up partitioning. A new multilevel partitioning algorithm, named betweenness-based partitioning algorithm, is also presented as an implementation of top-down partitioning paradigm. An experimental evaluation of seven different real-world scale-free networks shows that the betweenness-based partitioning algorithm significantly outperforms the existing state-of-the-art approaches.展开更多
The objective of this study is to develop a unique modeling approach for fast assessment of massive soil erosion by water at a regional scale in the Loess Plateau, China. This approach relies on an understanding of bo...The objective of this study is to develop a unique modeling approach for fast assessment of massive soil erosion by water at a regional scale in the Loess Plateau, China. This approach relies on an understanding of both regional patterns of soil loss and its impact factors in the plateau area. Based on the regional characteristics of pre- cipitation, vegetation and land form, and with the use of Landsat TM and ground investigation data, the entire Loess Plateau was first divided into 3 380 Fundamental Assessment Units (FAUs) to adapt to this regional modeling and fast assessment. A set of easily available parameters reflecting relevant water erosion factors at a regional scale was then developed, in which dynamic and static factors were discriminated. ArcInfo GIS was used to integrate all es- sential data into a central database. A resulting mathematical model was established to link the sediment yields and the selected variables on the basis of FAUs through overlay in GIS and multiple regression analyses. The sensitivity analyses and validation results show that this approach works effectively in assessing large area soil erosion, and also helps to understand the regional associations of erosion and its impact factors, and thus might significantly contribute to planning and policymaking for a large area erosion control in the Loess Plateau.展开更多
Background: Promotion of Evidence-Based Practice (EBP) in nursing appears to be developing slowly. Research indicates that nurses’ beliefs in EBP may play an even more significant role than knowledge and resources in...Background: Promotion of Evidence-Based Practice (EBP) in nursing appears to be developing slowly. Research indicates that nurses’ beliefs in EBP may play an even more significant role than knowledge and resources in making implementation feasible. To address this issue, measurement of nurses’ beliefs regarding EBP is paramount. Aims and objectives: This study explores the internal consistency reliability and the construct factor structure of the Norwegian version of the original Evidence-Based Practice Beliefs Scale (EBP-BS). Methods: The study has a Non-experimental exploratory survey design. A Norwegian translation of the EBP-BS was tested in a convenience sample of 118 healthcare professionals (95% nurses) attending a continuing education program at a University College in Norway. The response rate was 95% (n = 112). The internal consistency of the scale was measured by Cronbach’s alpha, and an explorative Principal Component Analysis (PCA) was used to explore the construct structure. Results: The overall internal consistency of the EBP-BS was acceptable. The PCA indicated a four-factor structure. The psychometric properties of two of the factors were too weak for expanding to a four-factor model. Based on our investigation of the EBP-BS, we suggest a two-factor structure model. The factors were named 1) General knowledge and confidence concerning EBP and 2) Task specific beliefs in EBP. This finding differs from previous results that indicated a unidimensional structure. Conclusion: As a starting point, reliable and valid measurement of nurses’ beliefs about EBP is required in order to identify possible obstacles and to optimize implementation in the individual clinical setting. Our results indicate that the EBP-BS has a two-factor structure. Further exploration of the factor structure is needed. Further empirical research may contribute to the resolving of controversies concerning basic understandings of the concept of EBP.展开更多
To solve the problems of high memory occupation,low connectivity and poor resiliency against node capture,which existing in the random key pre-distribution techniques while applying to the large scale Wireless Sensor ...To solve the problems of high memory occupation,low connectivity and poor resiliency against node capture,which existing in the random key pre-distribution techniques while applying to the large scale Wireless Sensor Networks(WSNs),an Identity-Based Key Agreement Scheme(IBKAS) is proposed based on identity-based encryption and Elliptic Curve Diffie-Hellman(ECDH).IBKAS can resist man-in-the-middle attacks and node-capture attacks through encrypting the key agreement parameters using identity-based encryption.Theoretical analysis indicates that comparing to the random key pre-distribution techniques,IBKAS achieves significant improvement in key connectivity,communication overhead,memory occupation,and security strength,and also enables efficient secure rekeying and network expansion.Furthermore,we implement IBKAS for TinyOS-2.1.2 based on the MICA2 motes,and the experiment results demonstrate that IBKAS is feasible for infrequent key distribution and rekeying for large scale sensor networks.展开更多
目的汉化孕妇尿失禁知信行量表(knowledge,attitude and practice assessment scale for pregnant women on UI,KAP-IU)并评价其信度、效度,为医护人员对孕妇尿失禁知信行情况的评估提供测量工具。方法2022年12月—2023年3月按照国际通...目的汉化孕妇尿失禁知信行量表(knowledge,attitude and practice assessment scale for pregnant women on UI,KAP-IU)并评价其信度、效度,为医护人员对孕妇尿失禁知信行情况的评估提供测量工具。方法2022年12月—2023年3月按照国际通用量表跨文化调适流程对量表进行汉化,形成中文版KAP-IU量表。2023年3月—6月采用便利抽样选取门诊就诊孕妇456例进行调查,基于Rasch模型和经典测量学检验指标进行信度、效度检验。结果430例孕妇完成研究。中文版KAP-IU量表共由23个条目构成,符合Rasch模型单维性假设,Rasch模型解释了66.1%的变异;个人和条目的分隔信度均>0.8,分隔指数≈3,所有条目加权的均方拟合统计量(information-weighted mean square fit statistic,Infit MNSQ)和未加权的均方拟合统计量(unweighted mean square fit statistic,Outfit MNSQ)均方值在0.473~1.611之间,点测量相关系数(point-measure correlation,Pt-Measure Corr)在0.293~0.731之间,个体能力均值比条目难度均值高0.343 Logits;总量表Cronbachα系数为0.783,3个维度(知识、态度和行为)的重测信度分别为0.751、0.815、0.760;条目水平内容效度指数(item-level CVI,I-CVI)为0.810~1.000;量表水平内容效度(scale-level CVI,S-CVI)为0.824。结论中文版KAP-IU量表在国内孕妇人群中经验证信度、效度良好,难度适中,可作为孕妇尿失禁知信行情况评估的可靠工具。展开更多
文摘Objective:To explore the effect of nursing intervention based on Caprini risk assessment scale for venous thromboembolism(VTE)in perioperative patients with liver cancer.Methods:A total of 128 hepatocellular cancer(HCC)patients who were hospitalized in our department from January 2021 to March 2022 and met the research criteria were selected.According to odd and even numbers in the order of inclusion,64 cases were divided into two groups:a control group and an observation group.The control group received routine nursing intervention during perioperative period,while the observation group received nursing intervention based on Caprini risk assessment scale for VTE.The incidence of VTE and complications were compared between the two groups.Results:The incidence of VTE and postoperative complications in the observation group were lower than those in the control group(P<0.05).Conclusion:Nursing intervention based on Caprini risk assessment scale for VTE can reduce the incidence of perioperative deep vein thrombosis and complications in patients with liver cancer;thus,it is worthy of clinical application.
文摘Amplitudes have been found to be a function of incident angle and offset. Hence data required to test for amplitude variation with angle or offset needs to have its amplitudes for all offsets preserved and not stacked. Amplitude Variation with Offset (AVO)/Amplitude Variation with Angle (AVA) is necessary to account for information in the offset/angle parameter (mode converted S-wave and P-wave velocities). Since amplitudes are a function of the converted S- and P-waves, it is important to investigate the dependence of amplitudes on the elastic (P- and S-waves) parameters from the seismic data. By modelling these effects for different reservoir fluids via fluid substitution, various AVO geobody classes present along the well and in the entire seismic cube can be observed. AVO analysis was performed on one test well (Well_1) and 3D pre-stack angle gathers from the Tano Basin. The analysis involves creating a synthetic model to infer the effect of offset scaling techniques on amplitude responses in the Tano basin as compared to the effect of unscaled seismic data. The spectral balance process was performed to match the amplitude spectra of all angle stacks to that of the mid (26°) stack on the test lines. The process had an effect primarily on the far (34° - 40°) stacks. The frequency content of these stacks slightly increased to match that of the near and mid stacks. In offset scaling process, the root mean square (RMS) amplitude comparison between the synthetic and seismic suggests that the amplitude of the far traces should be reduced relative to the nears by up to 16%. However, the exact scaler values depend on the time window considered. This suggests that the amplitude scaling with offset delivered from seismic processing is only approximately correct and needs to be checked with well synthetics and adjusted accordingly prior to use for AVO studies. The AVO attribute volumes generated were better at resolving anomalies on spectrally balanced and offset scaled data than data delivered from conventional processing. A typical class II AVO anomaly is seen along the test well from the cross-plot analysis and AVO attribute cube which indicates an oil filled reservoir.
文摘Timely detection of dynamical complexity changes in natural and man-made systems has deep scientific and practical meanings. We introduce a complexity measure for time series: the base-scale entropy. The definition directly applies to arbitrary real-word data. We illustrate our method on a practical speech signal and in a theoretical chaotic system. The results show that the simple and easily calculated measure of base-scale entropy can be effectively used to detect qualitative and quantitative dynamical changes.
基金the grants from National Tackle Key Science and Technology Program sduring the Ninth Five-Year Plan Period, No.96-903-01-11the grants from State Administration of Traditional Chinese Medicine of People's Republic of China,No.00-01LP16
文摘BACKGROUND: Convalescence is an important stage of stroke treatment. A lot of patients have somatic and mental disorders at various degrees. The primary standard can only reflect partial conditions of somatic disorder; in addition, multiple dimensions of patients at the phase of stroke convalescence are further observed by using a lot of standards, such as signs and symptoms of traditional Chinese medicine, daily activity and psychological status. OBJECTIVE: To analyze the outcome assessments of the cases of stroke convalescence measured with different criteria consisting of various dimensions by a cross-sectional investigation of the condition of stroke convalescent patients. DESIGN: Scale evaluation. SETTING: Departments of Clinical Epidemiology Exploratory Development and Neurology, the Second Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine; National Center for Training of Design, Measurement and Evaluation in Clinical Research,Guangzhou University of Traditional Chinese Medicine. PARTICIPANTS: A total of 194 stroke convalescent patients treated in the Second Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine from July 26, 2000 to February 28, 2001 were taken as subjects of the study. There were 126 males and 68 females aged from 40 to 89 years, and the illness course ranged from 14 to 181 days. All patients met diagnosis-treatment criteria of stroke (the second version)[DTCS(V2.0)] and various kinds of diagnostic points of cerebrovascular diseases; moreover, all patients provided confirmed consents. METHODS: They were assessed by assessment methods including the following assessment instruments: DTCS(V2.0), self-designed scale of traditional Chinese medicine (TCM) symptoms (28 symptoms and physical signs were scored as 0, 1, 2 marks from none to severity), modified Edinburgh-Scandinavia stroke scale (a total of 45 marks, 0 to 15 marks as mild defect, 16 to 30 as moderate defect, 31 to 45 as severe defect), modified Barthel activities of daily life (ADL) index (a total of 100 marks, less than 60 marks as unable self-care), vitality and mental health (subscales derived from Health Survey Questionnaire, SF-36). The collected data from scales and inter-scale correlation were processed by the statistic methods mainly including descriptive analysis, Spearmen correlation analysis, factor analysis, etc. MAIN OUTCOME MEASURES: ① Average scores of scales and criteria; ② correlation between modified Edinburgh-Scandinavia stroke scale and other scales. RESULTS: All of the patients completed the assessment, and analyzed in the final analysis. ① The average scores of the scales and criteria: The average scores of DTCS(V2.0), self-designed scale of TCM symptoms, modified Edinburgh-Scandinavia stroke scale, modified Barthel ADL index, vitality and mental health scales were 6.51±6.29, 13.73±6.97, 7.56±7.35, 63.58±23.68, 52.79±23.32 and 62.83±22.75 respectively. ② Correlation between modified Edinburgh-Scandinavia stroke scale and other scales: The Spearman correlation coefficients (R ’) of modified Edinburgh-Scandinavia stroke scale with diagnosis-treatment criteria of stroke, scales of TCM symptoms, modified Barthel ADL index, vitality scale and mental health scale were 20.885, 0.302, -0.824, -0.294 and -0.258 respectively. CONCLUSION: The modified Edinburgh-Scandinavia stroke scale and DTCS(V2.0) shared the same assessment dimension, so they can be mutually alternated in some clinical practices. Discrepancy in measurements of health status was gained due to the diverse dimensions applied in outcome assessments. It is necessary to build up a multi-dimensional assessment criteria system, such as signs and symptoms, daily activities and psychological status, for assessing the stroke convalescent cases in a more comprehensive scope and reflecting the efficacy of TCM treatment scientifically.
文摘The closure of a turbulence field is a longstanding fundamental problem, while most closure models are introduced in spectral space. Inspired by Chou's quasi-normal closure method in spectral space, we propose an analytical closure model for isotropic turbulence based on the extended scale similarity theory of the velocity structure function in physical space. The assumptions and certain approximations are justified with direct numerical simulation. The asymptotic scaling properties are reproduced by this new closure method, in comparison to the classical Batchelor model.
基金supported by the National Science Foundation of China(No.50875078)
文摘An approach based on multi-scale chirplet sparse signal decomposition is proposed to separate the multi-component polynomial phase signals,and estimate their instantaneous frequencies.In this paper,we have generated a family of multi-scale chirplet functions which provide good local correlations of chirps over shorter time interval.At every decomposition stage,we build the so-called family of chirplets and our idea is to use a structured algorithm which exploits information in the family to chain chirplets together adaptively as to form the polynomial phase signal component whose correlation with the current residue signal is largest.Simultaneously,the polynomial instantaneous frequency is estimated by connecting the linear frequency of the chirplet functions adopted in the current separation.Simulation experiment demonstrated that this method can separate the components of the multi-component polynomial phase signals effectively even in the low signal-to-noise ratio condition,and estimate its instantaneous frequency accurately.
文摘Successful modeling and/or design of engineering systems often requires one to address the impact of multiple "design variables" on the prescribed outcome.There are often multiple,competing objectives based on which we assess the outcome of optimization.Since accurate,high fidelity models are typically time consuming and computationally expensive,comprehensive evaluations can be conducted only if an efficient framework is available.Furthermore,informed decisions of the model/hardware's overall performance rely on an adequate understanding of the global,not local,sensitivity of the individual design variables on the objectives.The surrogate-based approach,which involves approximating the objectives as continuous functions of design variables from limited data,offers a rational framework to reduce the number of important input variables,i.e.,the dimension of a design or modeling space.In this paper,we review the fundamental issues that arise in surrogate-based analysis and optimization,highlighting concepts,methods,techniques,as well as modeling implications for mechanics problems.To aid the discussions of the issues involved,we summarize recent efforts in investigating cryogenic cavitating flows,active flow control based on dielectric barrier discharge concepts,and lithium(Li)-ion batteries.It is also stressed that many multi-scale mechanics problems can naturally benefit from the surrogate approach for "scale bridging."
基金supported by the National Science Foundation for Distinguished Young Scholars of China(Grant Nos.61003082 and 60903059)the National Natural Science Foundation of China(Grant No.60873014)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(Grant No.60921062)
文摘Many real-world networks are found to be scale-free. However, graph partition technology, as a technology capable of parallel computing, performs poorly when scale-free graphs are provided. The reason for this is that traditional partitioning algorithms are designed for random networks and regular networks, rather than for scale-free networks. Multilevel graph-partitioning algorithms are currently considered to be the state of the art and are used extensively. In this paper, we analyse the reasons why traditional multilevel graph-partitioning algorithms perform poorly and present a new multilevel graph-partitioning paradigm, top down partitioning, which derives its name from the comparison with the traditional bottom-up partitioning. A new multilevel partitioning algorithm, named betweenness-based partitioning algorithm, is also presented as an implementation of top-down partitioning paradigm. An experimental evaluation of seven different real-world scale-free networks shows that the betweenness-based partitioning algorithm significantly outperforms the existing state-of-the-art approaches.
基金Under the auspices of Northeast Normal University Sci-tech Innovation Incubation Program(No.NENU-STC08017)European Commission FP7 Project―PRACTICE(No.ENVI-2008-226818)
文摘The objective of this study is to develop a unique modeling approach for fast assessment of massive soil erosion by water at a regional scale in the Loess Plateau, China. This approach relies on an understanding of both regional patterns of soil loss and its impact factors in the plateau area. Based on the regional characteristics of pre- cipitation, vegetation and land form, and with the use of Landsat TM and ground investigation data, the entire Loess Plateau was first divided into 3 380 Fundamental Assessment Units (FAUs) to adapt to this regional modeling and fast assessment. A set of easily available parameters reflecting relevant water erosion factors at a regional scale was then developed, in which dynamic and static factors were discriminated. ArcInfo GIS was used to integrate all es- sential data into a central database. A resulting mathematical model was established to link the sediment yields and the selected variables on the basis of FAUs through overlay in GIS and multiple regression analyses. The sensitivity analyses and validation results show that this approach works effectively in assessing large area soil erosion, and also helps to understand the regional associations of erosion and its impact factors, and thus might significantly contribute to planning and policymaking for a large area erosion control in the Loess Plateau.
文摘Background: Promotion of Evidence-Based Practice (EBP) in nursing appears to be developing slowly. Research indicates that nurses’ beliefs in EBP may play an even more significant role than knowledge and resources in making implementation feasible. To address this issue, measurement of nurses’ beliefs regarding EBP is paramount. Aims and objectives: This study explores the internal consistency reliability and the construct factor structure of the Norwegian version of the original Evidence-Based Practice Beliefs Scale (EBP-BS). Methods: The study has a Non-experimental exploratory survey design. A Norwegian translation of the EBP-BS was tested in a convenience sample of 118 healthcare professionals (95% nurses) attending a continuing education program at a University College in Norway. The response rate was 95% (n = 112). The internal consistency of the scale was measured by Cronbach’s alpha, and an explorative Principal Component Analysis (PCA) was used to explore the construct structure. Results: The overall internal consistency of the EBP-BS was acceptable. The PCA indicated a four-factor structure. The psychometric properties of two of the factors were too weak for expanding to a four-factor model. Based on our investigation of the EBP-BS, we suggest a two-factor structure model. The factors were named 1) General knowledge and confidence concerning EBP and 2) Task specific beliefs in EBP. This finding differs from previous results that indicated a unidimensional structure. Conclusion: As a starting point, reliable and valid measurement of nurses’ beliefs about EBP is required in order to identify possible obstacles and to optimize implementation in the individual clinical setting. Our results indicate that the EBP-BS has a two-factor structure. Further exploration of the factor structure is needed. Further empirical research may contribute to the resolving of controversies concerning basic understandings of the concept of EBP.
基金Supported by the National Basic Research Program of China(973 Program)(No.2011CB302903)the National Natural Science Foundation of China(No.61100213)+3 种基金the Key Program of Natural Science for Universities of Jiangsu Province(No.10KJA510035)the Specialized Research Fund for the Doctoral Program of Higher Education(20113223120007)the Science and Technology Program of Nanjing(201103003)the Postgraduate Innovation Project Foundation of Jiangsu Province(No.CXLX11_0411)
文摘To solve the problems of high memory occupation,low connectivity and poor resiliency against node capture,which existing in the random key pre-distribution techniques while applying to the large scale Wireless Sensor Networks(WSNs),an Identity-Based Key Agreement Scheme(IBKAS) is proposed based on identity-based encryption and Elliptic Curve Diffie-Hellman(ECDH).IBKAS can resist man-in-the-middle attacks and node-capture attacks through encrypting the key agreement parameters using identity-based encryption.Theoretical analysis indicates that comparing to the random key pre-distribution techniques,IBKAS achieves significant improvement in key connectivity,communication overhead,memory occupation,and security strength,and also enables efficient secure rekeying and network expansion.Furthermore,we implement IBKAS for TinyOS-2.1.2 based on the MICA2 motes,and the experiment results demonstrate that IBKAS is feasible for infrequent key distribution and rekeying for large scale sensor networks.
文摘目的汉化孕妇尿失禁知信行量表(knowledge,attitude and practice assessment scale for pregnant women on UI,KAP-IU)并评价其信度、效度,为医护人员对孕妇尿失禁知信行情况的评估提供测量工具。方法2022年12月—2023年3月按照国际通用量表跨文化调适流程对量表进行汉化,形成中文版KAP-IU量表。2023年3月—6月采用便利抽样选取门诊就诊孕妇456例进行调查,基于Rasch模型和经典测量学检验指标进行信度、效度检验。结果430例孕妇完成研究。中文版KAP-IU量表共由23个条目构成,符合Rasch模型单维性假设,Rasch模型解释了66.1%的变异;个人和条目的分隔信度均>0.8,分隔指数≈3,所有条目加权的均方拟合统计量(information-weighted mean square fit statistic,Infit MNSQ)和未加权的均方拟合统计量(unweighted mean square fit statistic,Outfit MNSQ)均方值在0.473~1.611之间,点测量相关系数(point-measure correlation,Pt-Measure Corr)在0.293~0.731之间,个体能力均值比条目难度均值高0.343 Logits;总量表Cronbachα系数为0.783,3个维度(知识、态度和行为)的重测信度分别为0.751、0.815、0.760;条目水平内容效度指数(item-level CVI,I-CVI)为0.810~1.000;量表水平内容效度(scale-level CVI,S-CVI)为0.824。结论中文版KAP-IU量表在国内孕妇人群中经验证信度、效度良好,难度适中,可作为孕妇尿失禁知信行情况评估的可靠工具。