With the popularity of the Internet of Vehicles(IoV),a large amount of data is being generated every day.How to securely share data between the IoV operator and various value-added service providers becomes one of the...With the popularity of the Internet of Vehicles(IoV),a large amount of data is being generated every day.How to securely share data between the IoV operator and various value-added service providers becomes one of the critical issues.Due to its flexible and efficient fine-grained access control feature,Ciphertext-Policy Attribute-Based Encryption(CP-ABE)is suitable for data sharing in IoV.However,there are many flaws in most existing CP-ABE schemes,such as attribute privacy leakage and key misuse.This paper proposes a Traceable and Revocable CP-ABE-based Data Sharing with Partially hidden policy for IoV(TRE-DSP).A partially hidden access structure is adopted to hide sensitive user attribute values,and attribute categories are sent along with the ciphertext to effectively avoid privacy exposure.In addition,key tracking and malicious user revocation are introduced with broadcast encryption to prevent key misuse.Since the main computation task is outsourced to the cloud,the burden of the user side is relatively low.Analysis of security and performance demonstrates that TRE-DSP is more secure and practical for data sharing in IoV.展开更多
Hidden champions play a critical role in China’s efforts to overcome technological and industrial“chokepoints”.These enterprises are pivotal for breaking free from Western technological embargoes,avoiding entrapmen...Hidden champions play a critical role in China’s efforts to overcome technological and industrial“chokepoints”.These enterprises are pivotal for breaking free from Western technological embargoes,avoiding entrapment in low-value-added production,and driving industrial upgrading.Given the distinct market environment in which China’s hidden champions have emerged,it is both timely and practically significant to examine their growth trajectories and underlying mechanisms.This study adopts a resource allocation perspective to investigate the development path of Chinese manufacturing enterprises into hidden champions,using a vertical case study of Hailiya Group.The findings reveal that such enterprises achieve hidden champion status by vertically concentrating on niche markets while harnessing technological potential and horizontally diversifying their technology application scenarios.Their growth follows a“T-shaped”strategy,combining vertical specialization in a focused market with horizontal expansion into new applications.Four critical mechanisms underpin the rise of manufacturing hidden champions:market niche positioning,innovation-driven focus,application scenario expansion,and ecosystem development.Specifically,these enterprises strategically target niche markets,establish a technology-oriented competitive edge,broaden technology applications to unlock new profit opportunities,and develop collaborative ecosystems to share resources and drive industrial advancement.This paper not only extends the interpretive boundaries of resource allocation theory but also offers fresh insights into the emergence of Chinese manufacturing enterprises as hidden champions,enriching our understanding of their unique growth dynamics.展开更多
Objectives This study aimed to examine the role of the hidden curriculum in transmitting the educational mission and its impacts on nursing students’professional socialization.Methods This constructivist grounded the...Objectives This study aimed to examine the role of the hidden curriculum in transmitting the educational mission and its impacts on nursing students’professional socialization.Methods This constructivist grounded theory study involved twenty-six students and five faculty members from a century-old nursing school in Macao.Semi-structured interviews examined the factors influencing nursing students’choice of a specific nursing school and their general learning experiences in nursing studies.Open and focused coding was employed to develop categories and concepts that capture the nuances of how the hidden curriculum influences students’personal experiences,perceptions,and values related to developing their professional identities.The data analysis was guided by the“Community of Practice”model.Results The educational mission fostered a hidden curriculum that emphasized nurturing qualities and social responsibilities,creating a family-like learning environment that positively influenced the professional socialization of nursing students.Under the core theme of“becoming a family,”two sub-themes emerged:“student-peer interactions-fostering sisterly/brotherly learning partnerships”and“student-faculty interactions–faculty’s acting as parenting instructors.”While the hidden curriculum promoted a democratic and egalitarian learning atmosphere among student-peers,it simultaneously reinforced hierarchical power dynamics among senior-junior students and student-faculty relationships,mirroring the power-based interpersonal dynamics often found in traditional Chinese families.Conclusions Explicating the educational mission can help shape a hidden curriculum that benefits nursing students’professional socialization.Faculty members should reflect on the power inequalities reproduced by the hidden curriculum and establish appropriate boundaries in student-faculty relationships.展开更多
Large basins are currently the global focus for geothermal development,with their hydrothermal system being controlled by a variety of factors,such as basement relief and fracture development.Donglihu is located at th...Large basins are currently the global focus for geothermal development,with their hydrothermal system being controlled by a variety of factors,such as basement relief and fracture development.Donglihu is located at the north of the Cangxian uplift in the North China Basin,the concentrated geothermal resource development zone in North China.This study systematically collects temperature logging data and long-term dynamic monitoring of water level and water quality as well as group well tracer test data carried out in this area in recent years,on the basis of which the hydrothermal controlling role of the deep hidden faults is systematically analyzed.The results show that the Cangdong fault communicates with different geothermal reservoirs in the shallow part and plays a specific role in the water-heat channel of the local area.As a result,the high-value area of the geothermal temperature gradient in the sedimentary layer of the Donglihu area is distributed around the Cangdong fault.The geothermal reservoir temperature of the Minghuazhen Formation within the influence of the fault is also significantly higher than the regional average,the hydraulic head of different geothermal reservoirs showing a consistent and synergistic trend.However,the water quality has been stable for many years without any apparent changes.This understanding has a particular significance for further deepening understanding of the geothermal genesis mechanism in sedimentary basins and guiding future geothermal exploration and development in the Donglihu area.展开更多
The load profile is a key characteristic of the power grid and lies at the basis for the power flow control and generation scheduling.However,due to the wide adoption of internet-of-things(IoT)-based metering infrastr...The load profile is a key characteristic of the power grid and lies at the basis for the power flow control and generation scheduling.However,due to the wide adoption of internet-of-things(IoT)-based metering infrastructure,the cyber vulnerability of load meters has attracted the adversary’s great attention.In this paper,we investigate the vulnerability of manipulating the nodal prices by injecting false load data into the meter measurements.By taking advantage of the changing properties of real-world load profile,we propose a deeply hidden load data attack(i.e.,DH-LDA)that can evade bad data detection,clustering-based detection,and price anomaly detection.The main contributions of this work are as follows:(i)We design a stealthy attack framework that exploits historical load patterns to generate load data with minimal statistical deviation from normalmeasurements,thereby maximizing concealment;(ii)We identify the optimal time window for data injection to ensure that the altered nodal prices follow natural fluctuations,enhancing the undetectability of the attack in real-time market operations;(iii)We develop a resilience evaluation metric and formulate an optimization-based approach to quantify the electricity market’s robustness against DH-LDAs.Our experiments show that the adversary can gain profits from the electricity market while remaining undetected.展开更多
Scalar fields should have no spin angular momentum according to conventional textbook understandings inclassical field theory.Yet,recent studies demonstrate the undoubted existence of wave spin endowed by acousticand ...Scalar fields should have no spin angular momentum according to conventional textbook understandings inclassical field theory.Yet,recent studies demonstrate the undoubted existence of wave spin endowed by acousticand elastic longitudinal waves,which are of irrotational curl-free nature without vorticity and can be describedby scalar fields.Moreover,the conventional theory cannot even answer the question of whether wave spin existsin dissipative fields,given the ubiquitous dissipation in reality.Here,to resolve the seeming paradox and answerthe challenging question,we uncover the origin of wave spin in scalar fields beyond traditional formalism byclarifying that the presence of higher-order derivatives in scalar field Lagrangians can give rise to non-vanishingwave spin.For“spinless”scalar fields of only first-order derivatives,we can make the hidden wave spin emergeby revealing a latent field that leads to the original field through a time derivative,thus giving higher-order termsin Lagrangian.Based on the standard Noether theorem approach,we exemplify the wave spin for unconventionaldrifted acoustic fields,and even for dissipative media,in scalar fields with higher-order derivative Lagrangian.The results would prompt people to build more comprehensive and fundamental understandings of structuralwave spin in classical fields.展开更多
1 In 2024,audiences were treated to something very special:new music by Wolfgang Amadeus Mozart.That's right-new Mozart music!2 Leipzig Municipal Libraries announced their exciting find.Researchers came across thi...1 In 2024,audiences were treated to something very special:new music by Wolfgang Amadeus Mozart.That's right-new Mozart music!2 Leipzig Municipal Libraries announced their exciting find.Researchers came across this lost work while updating the Köchel catalogue,a list of Mozart's compositions.The piece is a seven⁃movement string trio,written in the mid to late 1760s,when Mozart was very young.The handwritten manuscript,titled Serenate ex C,uses dark brown ink on off⁃white paper.Now,it's been renamed Ganz kleine Nachtmusik and lasts about 12 minutes.展开更多
Achieving the dual carbon goal through energy transition has become a global consensus.The increasingly recognized of mineral resources is increasingly recognized due to their role in determining the pace of energy tr...Achieving the dual carbon goal through energy transition has become a global consensus.The increasingly recognized of mineral resources is increasingly recognized due to their role in determining the pace of energy transition.China has a leading capacity in the production and processing of certain minerals.However,because the major sources are abroad,China still faces certain disadvantages in acquiring upstream resources.In response to the complex international situation and high consumption demand。展开更多
Objective Identification of the risk factors for extraordinary hidden blood loss(HBL) could clarify the underlying causes and provide more appropriate management. This study aims to identify the predictors of HBL in s...Objective Identification of the risk factors for extraordinary hidden blood loss(HBL) could clarify the underlying causes and provide more appropriate management. This study aims to identify the predictors of HBL in spinal surgery.Methods Medical records were retrospectively retrieved to collect the data of patients who undergoing posterior thoracic and lumbar fusion surgery or scoliosis surgery. Demographic information, perioperative visible blood loss volume, as well as laboratory results were recorded. The patients receiving fusion surgery or scoliosis surgery were further divided into the HBL positive subgroup and the HBL negative subgroup. Differences in the variables between the groups were then analyzed. Binary logistic regression analysis was performed to determine independent risk factors associated with HBL.Results For patients undergoing posterior spinal surgery, the independent risk factors associated with HBL were autologous transfusion(for fusion surgery P = 0.011, OR: 2.627, 95%CI: 1.574-2.782; for scoliosis surgery P < 0.001, OR: 2.268, 95%CI: 2.143-2.504) and allogeneic transfusion(for fusion surgery P < 0.001, OR: 6.487, 95%CI: 2.349-17.915; for scoliosis surgery P < 0.001, OR: 3.636, 95%CI: 2.389-5.231).Conclusion Intraoperative blood transfusion might be an early-warning indicator for perioperative HBL.展开更多
The existing ontology mapping methods mainly consider the structure of the ontology and the mapping precision is lower to some extent. According to statistical theory, a method which is based on the hidden Markov mode...The existing ontology mapping methods mainly consider the structure of the ontology and the mapping precision is lower to some extent. According to statistical theory, a method which is based on the hidden Markov model is presented to establish ontology mapping. This method considers concepts as models, and attributes, relations, hierarchies, siblings and rules of the concepts as the states of the HMM, respectively. The models corresponding to the concepts are built by virtue of learning many training instances. On the basis of the best state sequence that is decided by the Viterbi algorithm and corresponding to the instance, mapping between the concepts can be established by maximum likelihood estimation. Experimental results show that this method can improve the precision of heterogeneous ontology mapping effectively.展开更多
The use of hidden conditional random fields （HCRFs） for tone modeling is explored. The tone recognition performance is improved using HCRFs by taking advantage of intra-syllable dynamic, inter-syllable dynamic and d...The use of hidden conditional random fields （HCRFs） for tone modeling is explored. The tone recognition performance is improved using HCRFs by taking advantage of intra-syllable dynamic, inter-syllable dynamic and duration features. When the tone model is integrated into continuous speech recognition, the discriminative model weight training （DMWT） is proposed. Acoustic and tone scores are scaled by model weights discriminatively trained by the minimum phone error （MPE） criterion. Two schemes of weight training are evaluated and a smoothing technique is used to make training robust to overtraining problem. Experiments show that the accuracies of tone recognition and large vocabulary continuous speech recognition （LVCSR） can be improved by the HCRFs based tone model. Compared with the global weight scheme, continuous speech recognition can be improved by the discriminative trained weight combinations.展开更多
A parameter estimation algorithm of the continuous hidden Markov model isintroduced and the rigorous proof of its convergence is also included. The algorithm uses theViterbi algorithm instead of K-means clustering use...A parameter estimation algorithm of the continuous hidden Markov model isintroduced and the rigorous proof of its convergence is also included. The algorithm uses theViterbi algorithm instead of K-means clustering used in the segmental K-means algorithm to determineoptimal state and branch sequences. Based on the optimal sequence, parameters are estimated withmaximum-likelihood as objective functions. Comparisons with the traditional Baum-Welch and segmentalK-means algorithms on various aspects, such as optimal objectives and fundamentals, are made. Allthree algorithms are applied to face recognition. Results indicate that the proposed algorithm canreduce training time with comparable recognition rate and it is least sensitive to the training set.So its average performance exceeds the other two.展开更多
A hidden line removal algorithm for bi parametric surfaces is presented and illustrated by some experimental results. The enclosure test is done using area coordinates. A technique of moving box of encirclement is p...A hidden line removal algorithm for bi parametric surfaces is presented and illustrated by some experimental results. The enclosure test is done using area coordinates. A technique of moving box of encirclement is presented. It is found that the algorithm is of general purpose, requires minimal computer storage, has high accuracy and simplicity, and is very easy to be implemented on a computer.展开更多
As the extension and supplement of explicit curriculum,the English hidden curriculum in higher vocational colleges plays animportant role in cultivating students' behaviors,stimulate their interest and arouse thei...As the extension and supplement of explicit curriculum,the English hidden curriculum in higher vocational colleges plays animportant role in cultivating students' behaviors,stimulate their interest and arouse their enthusiasm,initiative and creativity in learningEnglish.This paper analyzes the problems of English hidden curriculum construction in higher vocational colleges under the back-ground o"fInternet plus",and puts forward some corresponding countermeasures to bring the role of college English hidden curriculuminto full play.展开更多
We present a class of two-dimensional memristive maps with a cosine memristor. The memristive maps do not have any fixed points, so they belong to the category of nonlinear maps with hidden attractors. The rich dynami...We present a class of two-dimensional memristive maps with a cosine memristor. The memristive maps do not have any fixed points, so they belong to the category of nonlinear maps with hidden attractors. The rich dynamical behaviors of these maps are studied and investigated using different numerical tools, including phase portrait, basins of attraction,bifurcation diagram, and Lyapunov exponents. The two-parameter bifurcation analysis of the memristive map is carried out to reveal the bifurcation mechanism of its dynamical behaviors. Based on our extensive simulation studies, the proposed memristive maps can produce hidden periodic, chaotic, and hyper-chaotic attractors, exhibiting extremely hidden multistability, namely the coexistence of infinite hidden attractors, which was rarely observed in memristive maps. Potentially,this work can be used for some real applications in secure communication, such as data and image encryptions.展开更多
To improve the complexity of chaotic signals,in this paper we first put forward a new three-dimensional quadratic fractional-order multi-scroll hidden chaotic system,then we use the Adomian decomposition algorithm to ...To improve the complexity of chaotic signals,in this paper we first put forward a new three-dimensional quadratic fractional-order multi-scroll hidden chaotic system,then we use the Adomian decomposition algorithm to solve the proposed fractional-order chaotic system and obtain the chaotic phase diagrams of different orders,as well as the Lyaponov exponent spectrum,bifurcation diagram,and SE complexity of the 0.99-order system.In the process of analyzing the system,we find that the system possesses the dynamic behaviors of hidden attractors and hidden bifurcations.Next,we also propose a method of using the Lyapunov exponents to describe the basins of attraction of the chaotic system in the matlab environment for the first time,and obtain the basins of attraction under different order conditions.Finally,we construct an analog circuit system of the fractional-order chaotic system by using an equivalent circuit module of the fractional-order integral operators,thus realizing the 0.9-order multi-scroll hidden chaotic attractors.展开更多
基金supported by the National Natural Science Foundation of China(No.62272076)。
文摘With the popularity of the Internet of Vehicles(IoV),a large amount of data is being generated every day.How to securely share data between the IoV operator and various value-added service providers becomes one of the critical issues.Due to its flexible and efficient fine-grained access control feature,Ciphertext-Policy Attribute-Based Encryption(CP-ABE)is suitable for data sharing in IoV.However,there are many flaws in most existing CP-ABE schemes,such as attribute privacy leakage and key misuse.This paper proposes a Traceable and Revocable CP-ABE-based Data Sharing with Partially hidden policy for IoV(TRE-DSP).A partially hidden access structure is adopted to hide sensitive user attribute values,and attribute categories are sent along with the ciphertext to effectively avoid privacy exposure.In addition,key tracking and malicious user revocation are introduced with broadcast encryption to prevent key misuse.Since the main computation task is outsourced to the cloud,the burden of the user side is relatively low.Analysis of security and performance demonstrates that TRE-DSP is more secure and practical for data sharing in IoV.
基金supported by the following projects:The Youth Project of the National Natural Science Foundation of China(NSFC)“Research on Chinese Multinational Companies’Componovation under Resource Constraint:From a Dynamic Circulation Logic of Home and Host Countries”(Grant No.72102030)The Research Project of Humanities and Social Sciences of the Ministry of Education“Research on Chinese Multinational Companies’Learning by Doing Mechanism under Resource Constraint”(Grant No.21C10173022)The General Project of the China Postdoctoral Science Foundation“Research on the Realization Path and Motivations for the Domestic Replacement of Core Technologies for Chinese Manufacturing Enterprises”(Grant No.2022M720975).
文摘Hidden champions play a critical role in China’s efforts to overcome technological and industrial“chokepoints”.These enterprises are pivotal for breaking free from Western technological embargoes,avoiding entrapment in low-value-added production,and driving industrial upgrading.Given the distinct market environment in which China’s hidden champions have emerged,it is both timely and practically significant to examine their growth trajectories and underlying mechanisms.This study adopts a resource allocation perspective to investigate the development path of Chinese manufacturing enterprises into hidden champions,using a vertical case study of Hailiya Group.The findings reveal that such enterprises achieve hidden champion status by vertically concentrating on niche markets while harnessing technological potential and horizontally diversifying their technology application scenarios.Their growth follows a“T-shaped”strategy,combining vertical specialization in a focused market with horizontal expansion into new applications.Four critical mechanisms underpin the rise of manufacturing hidden champions:market niche positioning,innovation-driven focus,application scenario expansion,and ecosystem development.Specifically,these enterprises strategically target niche markets,establish a technology-oriented competitive edge,broaden technology applications to unlock new profit opportunities,and develop collaborative ecosystems to share resources and drive industrial advancement.This paper not only extends the interpretive boundaries of resource allocation theory but also offers fresh insights into the emergence of Chinese manufacturing enterprises as hidden champions,enriching our understanding of their unique growth dynamics.
基金supported by Foundation of Macao(No.G-BXX-00047-2112367-03)。
文摘Objectives This study aimed to examine the role of the hidden curriculum in transmitting the educational mission and its impacts on nursing students’professional socialization.Methods This constructivist grounded theory study involved twenty-six students and five faculty members from a century-old nursing school in Macao.Semi-structured interviews examined the factors influencing nursing students’choice of a specific nursing school and their general learning experiences in nursing studies.Open and focused coding was employed to develop categories and concepts that capture the nuances of how the hidden curriculum influences students’personal experiences,perceptions,and values related to developing their professional identities.The data analysis was guided by the“Community of Practice”model.Results The educational mission fostered a hidden curriculum that emphasized nurturing qualities and social responsibilities,creating a family-like learning environment that positively influenced the professional socialization of nursing students.Under the core theme of“becoming a family,”two sub-themes emerged:“student-peer interactions-fostering sisterly/brotherly learning partnerships”and“student-faculty interactions–faculty’s acting as parenting instructors.”While the hidden curriculum promoted a democratic and egalitarian learning atmosphere among student-peers,it simultaneously reinforced hierarchical power dynamics among senior-junior students and student-faculty relationships,mirroring the power-based interpersonal dynamics often found in traditional Chinese families.Conclusions Explicating the educational mission can help shape a hidden curriculum that benefits nursing students’professional socialization.Faculty members should reflect on the power inequalities reproduced by the hidden curriculum and establish appropriate boundaries in student-faculty relationships.
基金funded by Public Interest Monitoring Project(No.XCSD-2024-317)of the Tianjin Municipal Bureau of Planning and Natural Resources。
文摘Large basins are currently the global focus for geothermal development,with their hydrothermal system being controlled by a variety of factors,such as basement relief and fracture development.Donglihu is located at the north of the Cangxian uplift in the North China Basin,the concentrated geothermal resource development zone in North China.This study systematically collects temperature logging data and long-term dynamic monitoring of water level and water quality as well as group well tracer test data carried out in this area in recent years,on the basis of which the hydrothermal controlling role of the deep hidden faults is systematically analyzed.The results show that the Cangdong fault communicates with different geothermal reservoirs in the shallow part and plays a specific role in the water-heat channel of the local area.As a result,the high-value area of the geothermal temperature gradient in the sedimentary layer of the Donglihu area is distributed around the Cangdong fault.The geothermal reservoir temperature of the Minghuazhen Formation within the influence of the fault is also significantly higher than the regional average,the hydraulic head of different geothermal reservoirs showing a consistent and synergistic trend.However,the water quality has been stable for many years without any apparent changes.This understanding has a particular significance for further deepening understanding of the geothermal genesis mechanism in sedimentary basins and guiding future geothermal exploration and development in the Donglihu area.
基金supported by the project Major Scientific and Technological Special Project of Guizhou Province([2024]014).
文摘The load profile is a key characteristic of the power grid and lies at the basis for the power flow control and generation scheduling.However,due to the wide adoption of internet-of-things(IoT)-based metering infrastructure,the cyber vulnerability of load meters has attracted the adversary’s great attention.In this paper,we investigate the vulnerability of manipulating the nodal prices by injecting false load data into the meter measurements.By taking advantage of the changing properties of real-world load profile,we propose a deeply hidden load data attack(i.e.,DH-LDA)that can evade bad data detection,clustering-based detection,and price anomaly detection.The main contributions of this work are as follows:(i)We design a stealthy attack framework that exploits historical load patterns to generate load data with minimal statistical deviation from normalmeasurements,thereby maximizing concealment;(ii)We identify the optimal time window for data injection to ensure that the altered nodal prices follow natural fluctuations,enhancing the undetectability of the attack in real-time market operations;(iii)We develop a resilience evaluation metric and formulate an optimization-based approach to quantify the electricity market’s robustness against DH-LDAs.Our experiments show that the adversary can gain profits from the electricity market while remaining undetected.
基金supported by the National Key R&D Program of China(Grant Nos.2022YFA1404400 and 2023YFA1406900)the Natural Science Foundation of Shanghai(Grant No.23ZR1481200)the Program of Shanghai Academic Research Leader(Grant No.23XD1423800)。
文摘Scalar fields should have no spin angular momentum according to conventional textbook understandings inclassical field theory.Yet,recent studies demonstrate the undoubted existence of wave spin endowed by acousticand elastic longitudinal waves,which are of irrotational curl-free nature without vorticity and can be describedby scalar fields.Moreover,the conventional theory cannot even answer the question of whether wave spin existsin dissipative fields,given the ubiquitous dissipation in reality.Here,to resolve the seeming paradox and answerthe challenging question,we uncover the origin of wave spin in scalar fields beyond traditional formalism byclarifying that the presence of higher-order derivatives in scalar field Lagrangians can give rise to non-vanishingwave spin.For“spinless”scalar fields of only first-order derivatives,we can make the hidden wave spin emergeby revealing a latent field that leads to the original field through a time derivative,thus giving higher-order termsin Lagrangian.Based on the standard Noether theorem approach,we exemplify the wave spin for unconventionaldrifted acoustic fields,and even for dissipative media,in scalar fields with higher-order derivative Lagrangian.The results would prompt people to build more comprehensive and fundamental understandings of structuralwave spin in classical fields.
文摘1 In 2024,audiences were treated to something very special:new music by Wolfgang Amadeus Mozart.That's right-new Mozart music!2 Leipzig Municipal Libraries announced their exciting find.Researchers came across this lost work while updating the Köchel catalogue,a list of Mozart's compositions.The piece is a seven⁃movement string trio,written in the mid to late 1760s,when Mozart was very young.The handwritten manuscript,titled Serenate ex C,uses dark brown ink on off⁃white paper.Now,it's been renamed Ganz kleine Nachtmusik and lasts about 12 minutes.
基金the General Project of the National Natural Science Foundation of China,“Research on the Method of CO_(2)Technology Economic Evaluation Based on Net Energy and Carbon Input-Output”(72274212)。
文摘Achieving the dual carbon goal through energy transition has become a global consensus.The increasingly recognized of mineral resources is increasingly recognized due to their role in determining the pace of energy transition.China has a leading capacity in the production and processing of certain minerals.However,because the major sources are abroad,China still faces certain disadvantages in acquiring upstream resources.In response to the complex international situation and high consumption demand。
文摘Objective Identification of the risk factors for extraordinary hidden blood loss(HBL) could clarify the underlying causes and provide more appropriate management. This study aims to identify the predictors of HBL in spinal surgery.Methods Medical records were retrospectively retrieved to collect the data of patients who undergoing posterior thoracic and lumbar fusion surgery or scoliosis surgery. Demographic information, perioperative visible blood loss volume, as well as laboratory results were recorded. The patients receiving fusion surgery or scoliosis surgery were further divided into the HBL positive subgroup and the HBL negative subgroup. Differences in the variables between the groups were then analyzed. Binary logistic regression analysis was performed to determine independent risk factors associated with HBL.Results For patients undergoing posterior spinal surgery, the independent risk factors associated with HBL were autologous transfusion(for fusion surgery P = 0.011, OR: 2.627, 95%CI: 1.574-2.782; for scoliosis surgery P < 0.001, OR: 2.268, 95%CI: 2.143-2.504) and allogeneic transfusion(for fusion surgery P < 0.001, OR: 6.487, 95%CI: 2.349-17.915; for scoliosis surgery P < 0.001, OR: 3.636, 95%CI: 2.389-5.231).Conclusion Intraoperative blood transfusion might be an early-warning indicator for perioperative HBL.
基金国家自然科学基金(the National Natural Science Foundation of China under Grant No.50279041)陕西省自然科学基金(the Natural Science Foundation of Shaanxi Province of China under Grant No.2005F07)。
基金The Weaponry Equipment Foundation of PLA Equipment Ministry (No51406020105JB8103)
文摘The existing ontology mapping methods mainly consider the structure of the ontology and the mapping precision is lower to some extent. According to statistical theory, a method which is based on the hidden Markov model is presented to establish ontology mapping. This method considers concepts as models, and attributes, relations, hierarchies, siblings and rules of the concepts as the states of the HMM, respectively. The models corresponding to the concepts are built by virtue of learning many training instances. On the basis of the best state sequence that is decided by the Viterbi algorithm and corresponding to the instance, mapping between the concepts can be established by maximum likelihood estimation. Experimental results show that this method can improve the precision of heterogeneous ontology mapping effectively.
文摘The use of hidden conditional random fields （HCRFs） for tone modeling is explored. The tone recognition performance is improved using HCRFs by taking advantage of intra-syllable dynamic, inter-syllable dynamic and duration features. When the tone model is integrated into continuous speech recognition, the discriminative model weight training （DMWT） is proposed. Acoustic and tone scores are scaled by model weights discriminatively trained by the minimum phone error （MPE） criterion. Two schemes of weight training are evaluated and a smoothing technique is used to make training robust to overtraining problem. Experiments show that the accuracies of tone recognition and large vocabulary continuous speech recognition （LVCSR） can be improved by the HCRFs based tone model. Compared with the global weight scheme, continuous speech recognition can be improved by the discriminative trained weight combinations.
文摘A parameter estimation algorithm of the continuous hidden Markov model isintroduced and the rigorous proof of its convergence is also included. The algorithm uses theViterbi algorithm instead of K-means clustering used in the segmental K-means algorithm to determineoptimal state and branch sequences. Based on the optimal sequence, parameters are estimated withmaximum-likelihood as objective functions. Comparisons with the traditional Baum-Welch and segmentalK-means algorithms on various aspects, such as optimal objectives and fundamentals, are made. Allthree algorithms are applied to face recognition. Results indicate that the proposed algorithm canreduce training time with comparable recognition rate and it is least sensitive to the training set.So its average performance exceeds the other two.
文摘A hidden line removal algorithm for bi parametric surfaces is presented and illustrated by some experimental results. The enclosure test is done using area coordinates. A technique of moving box of encirclement is presented. It is found that the algorithm is of general purpose, requires minimal computer storage, has high accuracy and simplicity, and is very easy to be implemented on a computer.
文摘As the extension and supplement of explicit curriculum,the English hidden curriculum in higher vocational colleges plays animportant role in cultivating students' behaviors,stimulate their interest and arouse their enthusiasm,initiative and creativity in learningEnglish.This paper analyzes the problems of English hidden curriculum construction in higher vocational colleges under the back-ground o"fInternet plus",and puts forward some corresponding countermeasures to bring the role of college English hidden curriculuminto full play.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11972173 and 12172340)。
文摘We present a class of two-dimensional memristive maps with a cosine memristor. The memristive maps do not have any fixed points, so they belong to the category of nonlinear maps with hidden attractors. The rich dynamical behaviors of these maps are studied and investigated using different numerical tools, including phase portrait, basins of attraction,bifurcation diagram, and Lyapunov exponents. The two-parameter bifurcation analysis of the memristive map is carried out to reveal the bifurcation mechanism of its dynamical behaviors. Based on our extensive simulation studies, the proposed memristive maps can produce hidden periodic, chaotic, and hyper-chaotic attractors, exhibiting extremely hidden multistability, namely the coexistence of infinite hidden attractors, which was rarely observed in memristive maps. Potentially,this work can be used for some real applications in secure communication, such as data and image encryptions.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61561022 and 61672226)。
文摘To improve the complexity of chaotic signals,in this paper we first put forward a new three-dimensional quadratic fractional-order multi-scroll hidden chaotic system,then we use the Adomian decomposition algorithm to solve the proposed fractional-order chaotic system and obtain the chaotic phase diagrams of different orders,as well as the Lyaponov exponent spectrum,bifurcation diagram,and SE complexity of the 0.99-order system.In the process of analyzing the system,we find that the system possesses the dynamic behaviors of hidden attractors and hidden bifurcations.Next,we also propose a method of using the Lyapunov exponents to describe the basins of attraction of the chaotic system in the matlab environment for the first time,and obtain the basins of attraction under different order conditions.Finally,we construct an analog circuit system of the fractional-order chaotic system by using an equivalent circuit module of the fractional-order integral operators,thus realizing the 0.9-order multi-scroll hidden chaotic attractors.
