Railway real estate is the fundamental element of railway transportation production and operation.Effective management and rational utilization of railway real estate is essential for railway asset operation.Based on ...Railway real estate is the fundamental element of railway transportation production and operation.Effective management and rational utilization of railway real estate is essential for railway asset operation.Based on the investigation of the requirements of railway real estate management and operation,combined with Beidou positioning,GIS(Geographic Information System),multi-source data fusion and other cutting-edge technologies,this paper puts forward the multi-dimensional dynamic statistical method of real estate information,the identification method of railway land occupation and the comprehensive evaluation method of real estate development and utilization potential,and build the railway real estate supervision and operation platform,design the function of the platform,so as to provide intelligent solutions for the railway real estate operation.展开更多
Background Virtual-reality(VR)fusion techniques have become increasingly popular in recent years,and several previous studies have applied them to laboratory education.However,without a basis for evaluating the effect...Background Virtual-reality(VR)fusion techniques have become increasingly popular in recent years,and several previous studies have applied them to laboratory education.However,without a basis for evaluating the effects of virtual-real fusion on VR in education,many developers have chosen to abandon this expensive and complex set of techniques.Methods In this study,we experimentally investigate the effects of virtual-real fusion on immersion,presence,and learning performance.Each participant was randomly assigned to one of three conditions:a PC environment(PCE)operated by mouse;a VR environment(VRE)operated by controllers;or a VR environment running virtual-real fusion(VR VRFE),operated by real hands.Results The analysis of variance(ANOVA)and t-test results for presence and self-efficacy show significant differences between the PCE*VR-VRFE condition pair.Furthermore,the results show significant differences in the intrinsic value of learning performance for pairs PCE*VR VRFE and VRE*VR-VRFE,and a marginally significant difference was found for the immersion group.Conclusions The results suggest that virtual-real fusion can offer improved immersion,presence,and self efficacy compared to traditional PC environments,as well as a better intrinsic value of learning performance compared to both PC and VR environments.The results also suggest that virtual-real fusion offers a lower sense of presence compared to traditional VR environments.展开更多
Virtualization has gained great acceptance in the server and cloud computing arena. In recent years, it has also been widely applied to real-time embedded systems with stringent timing constraints. We present a compre...Virtualization has gained great acceptance in the server and cloud computing arena. In recent years, it has also been widely applied to real-time embedded systems with stringent timing constraints. We present a comprehensive survey on real-time issues in virtualization for embedded systems, covering popular virtualization systems including KVM, Xen, L4 and others.展开更多
In the process of formulating the General Provisions of the Civil Law of P. R. China, the attribute of virtual property rights has changed from real rights to non-real rights. Article No. 127 thereof does not clarify ...In the process of formulating the General Provisions of the Civil Law of P. R. China, the attribute of virtual property rights has changed from real rights to non-real rights. Article No. 127 thereof does not clarify the nature of virtual property rights after all, and the place where virtual property is put in the "Civil Rights" chapter of General Provisions of the Civil Law makes the concept even more complex and confusing. The "relationships paradigm" protection of virtual property does not have a definite classification criterion, nor stands opposite to the "rights paradigm." There are two different ways to justify the "theory of virtual property as a real right" under the "rights paradigm" protection, namely, essentialism and consequentialism. The former resulted from utilizing features in a demonstration and identifying disposal rights with real rights, while the latter resulted from adherence to the dichotomy system of property rights comprising real rights and creditor's rights. From the perspective of larceny in Criminal Law and virtual property insurance in The Social Insurance Law, the attribute of virtual property rights is irrelevant to creditor's rights. The attribute of virtual property rights shall be defined as virtual property rights so that it can be included in the system of civil rights. The uniqueness of virtual property is enough to become an object of emerging civil rights; intangible property rights as a superordinate theoretical concept cannot reflect the essence of virtual property rights. The legislative frame of virtual property rights shall be comprised of the subject, object, exercise, publication and change of the rights.展开更多
This is an attempt to explain mRNA-dependent non-stationary semantic values of codons (triplets) and nucleotides (letters) in codon composition during protein biosynthesis. This explanation is realized by comparing th...This is an attempt to explain mRNA-dependent non-stationary semantic values of codons (triplets) and nucleotides (letters) in codon composition during protein biosynthesis. This explanation is realized by comparing the different protein codes of various biosystem taxa, and, comparing mitochondrial code with the standard code. An initial mRNA transcriptional virtuality (Virtual-Reality) is transformed into material reality at the level of translation of virtual triplets into real (material) amino acids or into a real stop command of protein biosynthesis. The transformation of virtuality into reality occurs de facto when the linguistic sign1 functions of the codon syhoms are realized in the 3’ nucleotide (wobbling nucleotide according to F. Crick) in the process of protein biosynthesis. This corresponds to the theoretical works of the authors of this article. Despite the illusory appearance of semantic arbitrariness during the operation of ribosomes in the mode of codon semantic non-stationarity, this phenomenon probably provides biosystems with an unusually high level of adaptability to changes in the external environment as well as to internal (mental) dynamics of neuron’s genome in the cerebral cortex. The genome’s non-stationarity properties at the nucleotide, codon, gene and mental levels have fractal structure and corresponding dimensions. The highest form of such fractality (with maximum dimension) is probably realized in the genomic continuum of neurons in the human cerebral cortex through this semantic Virtual-to-Real (VR) codon transcoding with the biosynthesis of short-living semantic proteins, as the equivalents of material thinking-consciousness. In fact, this is the language of the brain’s genome, that is, our own language. In this case, the same thing happens in natural, primarily mental (non-verbal) languages. Their materialization is recorded in vocables (sounding words) and in writing. Such writing is the amino acid sequence in the semantic proteins of the human cerebral cortex. Rapidly decaying, such proteins can leave a long-lasting “so-called” Schrödinger wave holographic memory in the cerebral cortex. The presented below study is purely theoretical and based on a logical approach. The topic of the study is very complex and is subject to further development.展开更多
In the last twenty years, China has experienced a rapid development in the real estate industry. The continuous rising house price causes many social and economic problems and draws a lot of attentions from academia, ...In the last twenty years, China has experienced a rapid development in the real estate industry. The continuous rising house price causes many social and economic problems and draws a lot of attentions from academia, business world and government. Many researchers shed light on this problem from different angles, but till today, it hasn’t been fully resolved. In this paper, we try to examine the real estate bubble from a virtual economic perspective. We think that the virtual feature of real estate alters its economic role from a purely living and working place to a financing instrument. We use the newest monthly data of China real estate market from 2006 to 2018 and estimate the relationship between the housing bubble and real estate industry virtualization. We identify a significant positive association between house price index and the purchase price of land in real estate investment. This result suggests that virtual feature of real estate has deepen the bubble problem in the industry and its virtualization degree appears to be closely related to the virtual feature of land and its price proportion to real estate investment.展开更多
Under the background of the era of rapid development of the meta-universe,the fusion of virtual and reality in new media art creation has become a key trend.Starting from the concept of meta-universe and new media art...Under the background of the era of rapid development of the meta-universe,the fusion of virtual and reality in new media art creation has become a key trend.Starting from the concept of meta-universe and new media art,this paper analyzes the connection between the two in depth,elaborates on the manifestation of the fusion of virtual and reality in new media art creation,explores the challenges and problems it faces,and puts forward coping strategies with the aim of providing theoretical support for the development of the creation of new media art under the context of the meta-universe,and promoting the innovation and progress of art creation.展开更多
The architecture of project management of distributed concurrent product design in a virtual enterprise is put forward. T he process of project management and its functions are presented. Product design process coo...The architecture of project management of distributed concurrent product design in a virtual enterprise is put forward. T he process of project management and its functions are presented. Product design process coordination is also discussed. First, based on the analysis of traditi onal project management, project management and coordination of distributed coop erative product design in the virtual enterprise is put forward. Then, aiming at the characteristics of a distributed concurrent product design process, the inh erent rules and complex interrelations in product development are studied. Accor dingly, the architecture of project management of distributed cooperative produc t design in a virtual enterprise is presented to adapt to distributed concurrent development of complex products. The main advantages of the architecture are al so discussed. Finally, the emphasis is placed on the project management process. Its main functions are set forth, such as project definition, task decompositio n and distribution, resource constraints and dynamic resource scheduling, proces s fusion, task scheduling and monitoring, project plan, cost and quality evaluat ion, etc.展开更多
AIM:To evaluate the usefulness of real-time virtual sonography(RVS)in biliary and pancreatic diseases.METHODS:This study included 15 patients with biliary and pancreatic diseases.RVS can be used to observe an ultrasou...AIM:To evaluate the usefulness of real-time virtual sonography(RVS)in biliary and pancreatic diseases.METHODS:This study included 15 patients with biliary and pancreatic diseases.RVS can be used to observe an ultrasound image in real time by merging the ultrasound image with a multiplanar reconstruction computed tomography(CT)image,using pre-scanned CT volume data.The ultrasound used was EUB-8500with a convex probe EUP-C514.The RVS images were evaluated based on 3 levels,namely,excellent,good and poor,by the displacement in position.RESULTS:By combining the objectivity of CT with free scanning using RVS,it was possible to easily interpret the relationship between lesions and the surrounding organs as well as the position of vascular structures.The resulting evaluation levels of the RVS images were12 excellent(pancreatic cancer,bile duct cancer,cholecystolithiasis and cholangiocellular carcinoma)and 3 good(pancreatic cancer and gallbladder cancer).Compared with conventional B-mode ultrasonography and CT,RVS images achieved a rate of 80%superior visualization and 20%better visualization.CONCLUSION:RVS has potential usefulness in objective visualization and diagnosis in the field of biliary and pancreatic diseases.展开更多
System optimization plays a crucial role in developing VR system after 3D modeling, affecting the system's Immersion and Interaction performance enormously. In this article, several key techniques of optimizing a ...System optimization plays a crucial role in developing VR system after 3D modeling, affecting the system's Immersion and Interaction performance enormously. In this article, several key techniques of optimizing a virtual mining system were discussed: optimizing 3D models to keep the polygon number in VR system within target hardware's processing ability; optimizing texture database to save texture memory with perfect visual effect; optimizing database hierarchy structure to accelerate model retrieval; and optimizing LOD hierarchy structure to speed up rendering.展开更多
Network virtual social life and social life of the intimate contact, gaining experience through the network are growing acceptance of a new kind of practice writing behavior. In this paper, closely related to the new ...Network virtual social life and social life of the intimate contact, gaining experience through the network are growing acceptance of a new kind of practice writing behavior. In this paper, closely related to the new direction of life experience of the Internet age forms, and characteristics of practical writing life experience development under the network environment and study of teaching strategy analysis, think the Internet+ provided by the social forms life mirror, fits the practical writing “material needs” obtaining through the network to the indirect way to gain life experience of social forms, and has become a new kind of practical writing teaching methods. Network life experience is not only a practical writing, and also will use literature writing, news writing, such as writing behavior.展开更多
Distributed real time surveillance control system is used especially in distributed computer measure and control system, mostly inwidely dispersed measure points without human surveillance. This paper describes theory...Distributed real time surveillance control system is used especially in distributed computer measure and control system, mostly inwidely dispersed measure points without human surveillance. This paper describes theory、construction、control strategy, stabilityanalysis of distributed real time supervisory control and data acquisition system, implements distributed measure signals collectionand design of supervisory control system. The realization of virtual instrument based on VC＋＋ can accomplish measurementsignals acquisition, storage, display and analysis, also the result of surveillance control system is provided, and shows thefunctional powerful agility of virtual instrument based on VC＋＋.展开更多
In order to solve complex algorithm that is difficult to achieve real-time processing of Multiband image fusion within large amount of data, a real-time image fusion system based on FPGA and multi-DSP is designed. Fiv...In order to solve complex algorithm that is difficult to achieve real-time processing of Multiband image fusion within large amount of data, a real-time image fusion system based on FPGA and multi-DSP is designed. Five-band image acquisition, image registration, image fusion and display output can be done within the system which uses FPGA as the main processor and the other three DSP as an algorithm processor. Making full use of Flexible and high-speed characteristics of FPGA, while an image fusion algorithm based on multi-wavelet transform is optimized and applied to the system. The final experimental results show that the frame rate of 15 Hz, with a resolution of 1392 × 1040 of the five-band image can be used by the system to complete processing within 41ms.展开更多
An Augmented virtual environment(AVE)is concerned with the fusion of real-time video with 3D models or scenes so as to augment the virtual environment.In this paper,a new approach to establish an AVE with a wide field...An Augmented virtual environment(AVE)is concerned with the fusion of real-time video with 3D models or scenes so as to augment the virtual environment.In this paper,a new approach to establish an AVE with a wide field of view is proposed,including real-time video projection,multiple video texture fusion and 3D visualization of moving objects.A new diagonally weighted algorithm is proposed to smooth the apparent gaps within the overlapping area between the two adjacent videos.A visualization method for the location and trajectory of a moving virtual object is proposed to display the moving object and its trajectory in the 3D virtual environment.The experimental results showed that the proposed set of algorithms are able to fuse multiple real-time videos with 3D models efficiently,and the experiment runs a 3D scene containing two million triangles and six real-time videos at around 55 frames per second on a laptop with 1GB of graphics card memory.In addition,a realistic AVE with a wide field of view was created based on the Digital Earth Science Platform by fusing three videos with a complex indoor virtual scene,visualizing a moving object and drawing its trajectory in the real time.展开更多
A simple method for calculating distance between a solid sphere and a constructive solid geometry (CSG) so lid primitive (including block, cone, cylinder, sphere, wedge and torus) is derived to support the collision ...A simple method for calculating distance between a solid sphere and a constructive solid geometry (CSG) so lid primitive (including block, cone, cylinder, sphere, wedge and torus) is derived to support the collision detection algorithm. By decomposing the whole space into relative positions and geometric features of the sphere and the primitive considered, closed form distance formula are got. These calculations are very useful in the real time collision detection in which primitives are used as bounding volumes of complex objects.展开更多
In the construction of Metaverses,sensors that are referred to as the“bridge of information transmission”,play a key role.The functionality and efficiency of today’s sensors,which operate in a manner similar to phy...In the construction of Metaverses,sensors that are referred to as the“bridge of information transmission”,play a key role.The functionality and efficiency of today’s sensors,which operate in a manner similar to physical sensing,are frequently constrained by their hardware and software.In this research,we proposed the Parallel Sensing framework,which includes background,concept,basic methods and typical application of parallel sensing.In our formulation,sensors are redefined as the integration of real physical sensors and virtual software-defined sensors based on parallel intelligence,in order to boost the performance of the sensors.Each sensor will have a parallel counterpart in the virtual world within the framework of parallel sensing.Digital sensors serve as the brain of sensors and maintain the same properties as physical sensors.Parallel sensing allows physical sensors to operate in discrete time periods to conserve energy,while cloud-based descriptive,predictive,and prescriptive sensors operate continuously to offer compensation data and serve as guardians.To better illustrate parallel sensing concept,we show some example applications of parallel sensing such as parallel vision,parallel point cloud and parallel light fields,both of which are designed by construct virtual sensors to extend small real data to virtual big data and then boost the performance of perception models.Experimental results demonstrate the effective of parallel sensing framework.The interaction between the real and virtual worlds enables sensors to operate actively,allowing them to intelligently adapt to various scenarios and ultimately attain the goal of“Cognitive,Parallel,Crypto,Federated,Social and Ecologic”6S sensing.展开更多
AIM:To develop a novel 3-dimensional(3D) virtual hepatectomy simulation software,Liversim,to visualize the real-time deformation of the liver.METHODS:We developed a novel real-time virtual hepatectomy simulation softw...AIM:To develop a novel 3-dimensional(3D) virtual hepatectomy simulation software,Liversim,to visualize the real-time deformation of the liver.METHODS:We developed a novel real-time virtual hepatectomy simulation software program called Liversim. The software provides 4 basic functions:viewing 3D models from arbitrary directions,changing the colors and opacities of the models,deforming the models based on user interaction,and incising the liver parenchyma and intrahepatic vessels based on user operations. From April 2010 through 2013,99 patients underwent virtual hepatectomies that used the conventional software program SYNAPSE VINCENT preoperatively. Between April 2012 and October 2013,11 patients received virtual hepatectomies using the novel software program Liversim; these hepatectomies were performed both preoperatively and at the same that the actual hepatectomy was performed in an operating room. The perioperative outcomes were analyzed between the patients for whom SYNAPSE VINCENT was used and those for whom Liversim wasused. Furthermore,medical students and surgical residents were asked to complete questionnaires regarding the new software.RESULTS:There were no obvious discrepancies(i.e.,the emergence of branches in the portal vein or hepatic vein or the depth and direction of the resection line) between our simulation and the actual surgery during the resection process. The median operating time was 304 min(range,110 to 846) in the VINCENT group and 397 min(range,232 to 497) in the Liversim group(P = 0.30). The median amount of intraoperative bleeding was 510 m L(range,18 to 5120) in the VINCENT group and 470 m L(range,130 to 1600) in the Liversim group(P = 0.44). The median postoperative stay was 12 d(range,6 to 100) in the VINCENT group and 13 d(range,9 to 21) in the Liversim group(P = 0.36). There were no significant differences in the preoperative outcomes between the two groups. Liversim was not found to be clinically inferior to SYNAPSE VINCENT. Both students and surgical residents reported that the Liversim image was almost the same as the actual hepatectomy.CONCLUSION:Virtual hepatectomy with real-time deformation of the liver using Liversim is useful for the safe performance of hepatectomies and for surgical education.展开更多
The Virtual Resistor based Active Damping(VR-AD) is widely employed in converters connected to the grid via LCL filters in order to mitigate the inherent resonance of the filters. Nevertheless, in digitally controlled...The Virtual Resistor based Active Damping(VR-AD) is widely employed in converters connected to the grid via LCL filters in order to mitigate the inherent resonance of the filters. Nevertheless, in digitally controlled systems, the PWM and the calculating delays modify the system characteristics in terms of frequency and phase, thus destabilizing the system and degrading the VR-AD performances, mainly in low switching frequencies. Moreover, the stability of the system is greatly affected under weak grid operation characterized by large grid impedance variation. This paper solves these problems by proposing a systematic, robust and optimized design procedure of voltage oriented PI control(VOC) with VRAD. The considered design procedure ensures robust control(sufficient stability margins) and high quality of grid current(reduced steady-state error and minimized THD value) despite the negative impact of digital time delay, grid impedance variation and filter parameters change. Simulation and experimental results are presented to show robustness and efficiency of the suggested design procedure.展开更多
In this paper, we investigate the influences of network delay on QoE (Quality of Experience) such as the operability of haptic interface device and the fairness between players for soft objects in a networked real-tim...In this paper, we investigate the influences of network delay on QoE (Quality of Experience) such as the operability of haptic interface device and the fairness between players for soft objects in a networked real-time game subjectively and objectively. We handle a networked balloon bursting game in which two players burst balloons (i.e., soft objects) in a 3D virtual space by using haptic interface devices, and the players compete for the number of burst balloons. As a result, we find that the operability depends on the network delay from the local terminal to the other terminal, and the fairness is mainly dependent on the difference in network delay between the players’ terminals. We confirm that there exists a trade-off relationship between the operability and the fairness. We also see that the contribution of the fairness is larger than that of the operability to the comprehensive quality (i.e., the weighted sum of the operability and fairness). Assessment results further show that the output timing of terminals should be adjusted to the terminal which has the latest output timing to maintain the fairness when the difference in network delay between the terminals is large. In this way, the comprehensive quality at each terminal can be maintained as high as possible.展开更多
基金supported by the Scientific and Technological Research and Development Plan of China Railway Beijing Group Co.,Ltd.(2022CT01).
文摘Railway real estate is the fundamental element of railway transportation production and operation.Effective management and rational utilization of railway real estate is essential for railway asset operation.Based on the investigation of the requirements of railway real estate management and operation,combined with Beidou positioning,GIS(Geographic Information System),multi-source data fusion and other cutting-edge technologies,this paper puts forward the multi-dimensional dynamic statistical method of real estate information,the identification method of railway land occupation and the comprehensive evaluation method of real estate development and utilization potential,and build the railway real estate supervision and operation platform,design the function of the platform,so as to provide intelligent solutions for the railway real estate operation.
基金the National Key Research and Development Program of China(2018YFB1004902)the National Natural Science Foundation of China(61772329,61373085)。
文摘Background Virtual-reality(VR)fusion techniques have become increasingly popular in recent years,and several previous studies have applied them to laboratory education.However,without a basis for evaluating the effects of virtual-real fusion on VR in education,many developers have chosen to abandon this expensive and complex set of techniques.Methods In this study,we experimentally investigate the effects of virtual-real fusion on immersion,presence,and learning performance.Each participant was randomly assigned to one of three conditions:a PC environment(PCE)operated by mouse;a VR environment(VRE)operated by controllers;or a VR environment running virtual-real fusion(VR VRFE),operated by real hands.Results The analysis of variance(ANOVA)and t-test results for presence and self-efficacy show significant differences between the PCE*VR-VRFE condition pair.Furthermore,the results show significant differences in the intrinsic value of learning performance for pairs PCE*VR VRFE and VRE*VR-VRFE,and a marginally significant difference was found for the immersion group.Conclusions The results suggest that virtual-real fusion can offer improved immersion,presence,and self efficacy compared to traditional PC environments,as well as a better intrinsic value of learning performance compared to both PC and VR environments.The results also suggest that virtual-real fusion offers a lower sense of presence compared to traditional VR environments.
文摘Virtualization has gained great acceptance in the server and cloud computing arena. In recent years, it has also been widely applied to real-time embedded systems with stringent timing constraints. We present a comprehensive survey on real-time issues in virtualization for embedded systems, covering popular virtualization systems including KVM, Xen, L4 and others.
基金a phase achievement of Research on the Legal Problem of Third Party Infringing Contract Conclusion Interestsa general item under the national social sciences foundation(item number:16BFX1l0)Research on Expansion of Non-normative Provisions in Civil Legislation,one of the national subjects on rule of law and legal theory(item number:16SFB3031)
文摘In the process of formulating the General Provisions of the Civil Law of P. R. China, the attribute of virtual property rights has changed from real rights to non-real rights. Article No. 127 thereof does not clarify the nature of virtual property rights after all, and the place where virtual property is put in the "Civil Rights" chapter of General Provisions of the Civil Law makes the concept even more complex and confusing. The "relationships paradigm" protection of virtual property does not have a definite classification criterion, nor stands opposite to the "rights paradigm." There are two different ways to justify the "theory of virtual property as a real right" under the "rights paradigm" protection, namely, essentialism and consequentialism. The former resulted from utilizing features in a demonstration and identifying disposal rights with real rights, while the latter resulted from adherence to the dichotomy system of property rights comprising real rights and creditor's rights. From the perspective of larceny in Criminal Law and virtual property insurance in The Social Insurance Law, the attribute of virtual property rights is irrelevant to creditor's rights. The attribute of virtual property rights shall be defined as virtual property rights so that it can be included in the system of civil rights. The uniqueness of virtual property is enough to become an object of emerging civil rights; intangible property rights as a superordinate theoretical concept cannot reflect the essence of virtual property rights. The legislative frame of virtual property rights shall be comprised of the subject, object, exercise, publication and change of the rights.
文摘This is an attempt to explain mRNA-dependent non-stationary semantic values of codons (triplets) and nucleotides (letters) in codon composition during protein biosynthesis. This explanation is realized by comparing the different protein codes of various biosystem taxa, and, comparing mitochondrial code with the standard code. An initial mRNA transcriptional virtuality (Virtual-Reality) is transformed into material reality at the level of translation of virtual triplets into real (material) amino acids or into a real stop command of protein biosynthesis. The transformation of virtuality into reality occurs de facto when the linguistic sign1 functions of the codon syhoms are realized in the 3’ nucleotide (wobbling nucleotide according to F. Crick) in the process of protein biosynthesis. This corresponds to the theoretical works of the authors of this article. Despite the illusory appearance of semantic arbitrariness during the operation of ribosomes in the mode of codon semantic non-stationarity, this phenomenon probably provides biosystems with an unusually high level of adaptability to changes in the external environment as well as to internal (mental) dynamics of neuron’s genome in the cerebral cortex. The genome’s non-stationarity properties at the nucleotide, codon, gene and mental levels have fractal structure and corresponding dimensions. The highest form of such fractality (with maximum dimension) is probably realized in the genomic continuum of neurons in the human cerebral cortex through this semantic Virtual-to-Real (VR) codon transcoding with the biosynthesis of short-living semantic proteins, as the equivalents of material thinking-consciousness. In fact, this is the language of the brain’s genome, that is, our own language. In this case, the same thing happens in natural, primarily mental (non-verbal) languages. Their materialization is recorded in vocables (sounding words) and in writing. Such writing is the amino acid sequence in the semantic proteins of the human cerebral cortex. Rapidly decaying, such proteins can leave a long-lasting “so-called” Schrödinger wave holographic memory in the cerebral cortex. The presented below study is purely theoretical and based on a logical approach. The topic of the study is very complex and is subject to further development.
文摘In the last twenty years, China has experienced a rapid development in the real estate industry. The continuous rising house price causes many social and economic problems and draws a lot of attentions from academia, business world and government. Many researchers shed light on this problem from different angles, but till today, it hasn’t been fully resolved. In this paper, we try to examine the real estate bubble from a virtual economic perspective. We think that the virtual feature of real estate alters its economic role from a purely living and working place to a financing instrument. We use the newest monthly data of China real estate market from 2006 to 2018 and estimate the relationship between the housing bubble and real estate industry virtualization. We identify a significant positive association between house price index and the purchase price of land in real estate investment. This result suggests that virtual feature of real estate has deepen the bubble problem in the industry and its virtualization degree appears to be closely related to the virtual feature of land and its price proportion to real estate investment.
文摘Under the background of the era of rapid development of the meta-universe,the fusion of virtual and reality in new media art creation has become a key trend.Starting from the concept of meta-universe and new media art,this paper analyzes the connection between the two in depth,elaborates on the manifestation of the fusion of virtual and reality in new media art creation,explores the challenges and problems it faces,and puts forward coping strategies with the aim of providing theoretical support for the development of the creation of new media art under the context of the meta-universe,and promoting the innovation and progress of art creation.
文摘The architecture of project management of distributed concurrent product design in a virtual enterprise is put forward. T he process of project management and its functions are presented. Product design process coordination is also discussed. First, based on the analysis of traditi onal project management, project management and coordination of distributed coop erative product design in the virtual enterprise is put forward. Then, aiming at the characteristics of a distributed concurrent product design process, the inh erent rules and complex interrelations in product development are studied. Accor dingly, the architecture of project management of distributed cooperative produc t design in a virtual enterprise is presented to adapt to distributed concurrent development of complex products. The main advantages of the architecture are al so discussed. Finally, the emphasis is placed on the project management process. Its main functions are set forth, such as project definition, task decompositio n and distribution, resource constraints and dynamic resource scheduling, proces s fusion, task scheduling and monitoring, project plan, cost and quality evaluat ion, etc.
文摘AIM:To evaluate the usefulness of real-time virtual sonography(RVS)in biliary and pancreatic diseases.METHODS:This study included 15 patients with biliary and pancreatic diseases.RVS can be used to observe an ultrasound image in real time by merging the ultrasound image with a multiplanar reconstruction computed tomography(CT)image,using pre-scanned CT volume data.The ultrasound used was EUB-8500with a convex probe EUP-C514.The RVS images were evaluated based on 3 levels,namely,excellent,good and poor,by the displacement in position.RESULTS:By combining the objectivity of CT with free scanning using RVS,it was possible to easily interpret the relationship between lesions and the surrounding organs as well as the position of vascular structures.The resulting evaluation levels of the RVS images were12 excellent(pancreatic cancer,bile duct cancer,cholecystolithiasis and cholangiocellular carcinoma)and 3 good(pancreatic cancer and gallbladder cancer).Compared with conventional B-mode ultrasonography and CT,RVS images achieved a rate of 80%superior visualization and 20%better visualization.CONCLUSION:RVS has potential usefulness in objective visualization and diagnosis in the field of biliary and pancreatic diseases.
文摘System optimization plays a crucial role in developing VR system after 3D modeling, affecting the system's Immersion and Interaction performance enormously. In this article, several key techniques of optimizing a virtual mining system were discussed: optimizing 3D models to keep the polygon number in VR system within target hardware's processing ability; optimizing texture database to save texture memory with perfect visual effect; optimizing database hierarchy structure to accelerate model retrieval; and optimizing LOD hierarchy structure to speed up rendering.
文摘Network virtual social life and social life of the intimate contact, gaining experience through the network are growing acceptance of a new kind of practice writing behavior. In this paper, closely related to the new direction of life experience of the Internet age forms, and characteristics of practical writing life experience development under the network environment and study of teaching strategy analysis, think the Internet+ provided by the social forms life mirror, fits the practical writing “material needs” obtaining through the network to the indirect way to gain life experience of social forms, and has become a new kind of practical writing teaching methods. Network life experience is not only a practical writing, and also will use literature writing, news writing, such as writing behavior.
文摘Distributed real time surveillance control system is used especially in distributed computer measure and control system, mostly inwidely dispersed measure points without human surveillance. This paper describes theory、construction、control strategy, stabilityanalysis of distributed real time supervisory control and data acquisition system, implements distributed measure signals collectionand design of supervisory control system. The realization of virtual instrument based on VC＋＋ can accomplish measurementsignals acquisition, storage, display and analysis, also the result of surveillance control system is provided, and shows thefunctional powerful agility of virtual instrument based on VC＋＋.
文摘In order to solve complex algorithm that is difficult to achieve real-time processing of Multiband image fusion within large amount of data, a real-time image fusion system based on FPGA and multi-DSP is designed. Five-band image acquisition, image registration, image fusion and display output can be done within the system which uses FPGA as the main processor and the other three DSP as an algorithm processor. Making full use of Flexible and high-speed characteristics of FPGA, while an image fusion algorithm based on multi-wavelet transform is optimized and applied to the system. The final experimental results show that the frame rate of 15 Hz, with a resolution of 1392 × 1040 of the five-band image can be used by the system to complete processing within 41ms.
基金Research presented in this paper was funded by the National Key Research and Development Program of China[grant numbers 2016YFB0501503 and 2016YFB0501502]Hainan Provincial Department of Science and Technology[grant number ZDKJ2016021].
文摘An Augmented virtual environment(AVE)is concerned with the fusion of real-time video with 3D models or scenes so as to augment the virtual environment.In this paper,a new approach to establish an AVE with a wide field of view is proposed,including real-time video projection,multiple video texture fusion and 3D visualization of moving objects.A new diagonally weighted algorithm is proposed to smooth the apparent gaps within the overlapping area between the two adjacent videos.A visualization method for the location and trajectory of a moving virtual object is proposed to display the moving object and its trajectory in the 3D virtual environment.The experimental results showed that the proposed set of algorithms are able to fuse multiple real-time videos with 3D models efficiently,and the experiment runs a 3D scene containing two million triangles and six real-time videos at around 55 frames per second on a laptop with 1GB of graphics card memory.In addition,a realistic AVE with a wide field of view was created based on the Digital Earth Science Platform by fusing three videos with a complex indoor virtual scene,visualizing a moving object and drawing its trajectory in the real time.
文摘A simple method for calculating distance between a solid sphere and a constructive solid geometry (CSG) so lid primitive (including block, cone, cylinder, sphere, wedge and torus) is derived to support the collision detection algorithm. By decomposing the whole space into relative positions and geometric features of the sphere and the primitive considered, closed form distance formula are got. These calculations are very useful in the real time collision detection in which primitives are used as bounding volumes of complex objects.
基金supported by the National Key R&D Program of China(2018AAA0101502)the Science and Technology Project of SGCC(State Grid Corporation of China):Fundamental Theory of Human-in-the-Loop Hybrid-Augmented Intelligence for Power Grid Dispatch and Control。
文摘In the construction of Metaverses,sensors that are referred to as the“bridge of information transmission”,play a key role.The functionality and efficiency of today’s sensors,which operate in a manner similar to physical sensing,are frequently constrained by their hardware and software.In this research,we proposed the Parallel Sensing framework,which includes background,concept,basic methods and typical application of parallel sensing.In our formulation,sensors are redefined as the integration of real physical sensors and virtual software-defined sensors based on parallel intelligence,in order to boost the performance of the sensors.Each sensor will have a parallel counterpart in the virtual world within the framework of parallel sensing.Digital sensors serve as the brain of sensors and maintain the same properties as physical sensors.Parallel sensing allows physical sensors to operate in discrete time periods to conserve energy,while cloud-based descriptive,predictive,and prescriptive sensors operate continuously to offer compensation data and serve as guardians.To better illustrate parallel sensing concept,we show some example applications of parallel sensing such as parallel vision,parallel point cloud and parallel light fields,both of which are designed by construct virtual sensors to extend small real data to virtual big data and then boost the performance of perception models.Experimental results demonstrate the effective of parallel sensing framework.The interaction between the real and virtual worlds enables sensors to operate actively,allowing them to intelligently adapt to various scenarios and ultimately attain the goal of“Cognitive,Parallel,Crypto,Federated,Social and Ecologic”6S sensing.
文摘AIM:To develop a novel 3-dimensional(3D) virtual hepatectomy simulation software,Liversim,to visualize the real-time deformation of the liver.METHODS:We developed a novel real-time virtual hepatectomy simulation software program called Liversim. The software provides 4 basic functions:viewing 3D models from arbitrary directions,changing the colors and opacities of the models,deforming the models based on user interaction,and incising the liver parenchyma and intrahepatic vessels based on user operations. From April 2010 through 2013,99 patients underwent virtual hepatectomies that used the conventional software program SYNAPSE VINCENT preoperatively. Between April 2012 and October 2013,11 patients received virtual hepatectomies using the novel software program Liversim; these hepatectomies were performed both preoperatively and at the same that the actual hepatectomy was performed in an operating room. The perioperative outcomes were analyzed between the patients for whom SYNAPSE VINCENT was used and those for whom Liversim wasused. Furthermore,medical students and surgical residents were asked to complete questionnaires regarding the new software.RESULTS:There were no obvious discrepancies(i.e.,the emergence of branches in the portal vein or hepatic vein or the depth and direction of the resection line) between our simulation and the actual surgery during the resection process. The median operating time was 304 min(range,110 to 846) in the VINCENT group and 397 min(range,232 to 497) in the Liversim group(P = 0.30). The median amount of intraoperative bleeding was 510 m L(range,18 to 5120) in the VINCENT group and 470 m L(range,130 to 1600) in the Liversim group(P = 0.44). The median postoperative stay was 12 d(range,6 to 100) in the VINCENT group and 13 d(range,9 to 21) in the Liversim group(P = 0.36). There were no significant differences in the preoperative outcomes between the two groups. Liversim was not found to be clinically inferior to SYNAPSE VINCENT. Both students and surgical residents reported that the Liversim image was almost the same as the actual hepatectomy.CONCLUSION:Virtual hepatectomy with real-time deformation of the liver using Liversim is useful for the safe performance of hepatectomies and for surgical education.
基金supported by the Tunisian Ministry of High Education and Research under Grant LSE-ENIT-LR11ES15
文摘The Virtual Resistor based Active Damping(VR-AD) is widely employed in converters connected to the grid via LCL filters in order to mitigate the inherent resonance of the filters. Nevertheless, in digitally controlled systems, the PWM and the calculating delays modify the system characteristics in terms of frequency and phase, thus destabilizing the system and degrading the VR-AD performances, mainly in low switching frequencies. Moreover, the stability of the system is greatly affected under weak grid operation characterized by large grid impedance variation. This paper solves these problems by proposing a systematic, robust and optimized design procedure of voltage oriented PI control(VOC) with VRAD. The considered design procedure ensures robust control(sufficient stability margins) and high quality of grid current(reduced steady-state error and minimized THD value) despite the negative impact of digital time delay, grid impedance variation and filter parameters change. Simulation and experimental results are presented to show robustness and efficiency of the suggested design procedure.
文摘In this paper, we investigate the influences of network delay on QoE (Quality of Experience) such as the operability of haptic interface device and the fairness between players for soft objects in a networked real-time game subjectively and objectively. We handle a networked balloon bursting game in which two players burst balloons (i.e., soft objects) in a 3D virtual space by using haptic interface devices, and the players compete for the number of burst balloons. As a result, we find that the operability depends on the network delay from the local terminal to the other terminal, and the fairness is mainly dependent on the difference in network delay between the players’ terminals. We confirm that there exists a trade-off relationship between the operability and the fairness. We also see that the contribution of the fairness is larger than that of the operability to the comprehensive quality (i.e., the weighted sum of the operability and fairness). Assessment results further show that the output timing of terminals should be adjusted to the terminal which has the latest output timing to maintain the fairness when the difference in network delay between the terminals is large. In this way, the comprehensive quality at each terminal can be maintained as high as possible.
