A PRIVACY-PRESERVING AUTHENTICATION SCHEME USING BIOMETRICS FOR PERVASIVE COMPUTING ENVIRONMENTS

In pervasive computing environments,users can get services anytime and anywhere,but the ubiquity and mobility of the environments bring new security challenges.The user and the service provider do not know each other in advance,they should mutually authenticate each other.The service provider prefers to authenticate the user based on his identity while the user tends to stay anonymous.Privacy and security are two important but seemingly contradictory objectives.As a result,a user prefers not to expose any sensitive information to the service provider such as his physical location,ID and so on when being authenticated.In this paper,a highly flexible mutual authentication and key establishment protocol scheme based on biometric encryption and Diffie-Hellman key exchange to secure interactions between a user and a service provider is proposed.Not only can a user's anonymous authentication be achieved,but also the public key cryptography operations can be reduced by adopting this scheme.Different access control policies for different services are enabled by using biometric encryption technique.The correctness of the proposed authentication and key establishment protocol is formally verified based on SVO logic.

Planning Management of Multiagent-based Distributed Open Computing Environment Model

ＰｌａｎｎｉｎｇＭａｎａｇｅｍｅｎｔｏｆＭｕｌｔｉａｇｅｎｔ┐ｂａｓｅｄＤｉｓｔｒｉｂｕｔｅｄＯｐｅｎＣｏｍｐｕｔｉｎｇＥｎｖｉｒｏｎｍｅｎｔＭｏｄｅｌＨｅＹａｎｘｉａｎｇ（何炎祥）（ＣｏｌｅｇｅｏｆＣｏｍｐｕｔｅｒＳｃｉｅｎｃｅａｎｄＴｅｃｈｎｏ...

Reversible Data Hiding for Medical Images in Cloud Computing Environments Based on Chaotic Hénon Map

Reversible data hiding techniques are capable of reconstructing the original cover image from stego-images. Recently, many researchers have focused on reversible data hiding to protect intellectual property rights. In this paper, we combine reversible data hiding with the chaotic Henon map as an encryption technique to achieve an acceptable level of confidentiality in cloud computing environments. And, Haar digital wavelet transformation （HDWT） is also applied to convert an image from a spatial domain into a frequency domain. And then the decimal of coefficients and integer of high frequency band are modified for hiding secret bits. Finally, the modified coefficients are inversely transformed to stego-images.

Parallel scheduling strategy of web-based spatial computing tasks in multi-core environment

In order to improve the concurrent access performance of the web-based spatial computing system in cluster,a parallel scheduling strategy based on the multi-core environment is proposed,which includes two levels of parallel processing mechanisms.One is that it can evenly allocate tasks to each server node in the cluster and the other is that it can implement the load balancing inside a server node.Based on the strategy,a new web-based spatial computing model is designed in this paper,in which,a task response ratio calculation method,a request queue buffer mechanism and a thread scheduling strategy are focused on.Experimental results show that the new model can fully use the multi-core computing advantage of each server node in the concurrent access environment and improve the average hits per second,average I/O Hits,CPU utilization and throughput.Using speed-up ratio to analyze the traditional model and the new one,the result shows that the new model has the best performance.The performance of the multi-core server nodes in the cluster is optimized;the resource utilization and the parallel processing capabilities are enhanced.The more CPU cores you have,the higher parallel processing capabilities will be obtained.

Computational fluid dynamics evaluation of the effect of different city designs on the wind environment of a downwind natural heritage site

Disturbance in wind regime and sand erosion deposition balance may lead to burial and eventual vanishing of a site.This study conducted 3D computational fluid dynamics(CFD)simulations to evaluate the effect of a proposed city design on the wind environment of the Crescent Spring,a downwind natural heritage site located in Dunhuang,Northwestern China.Satellite terrain data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer(ASTER)Digital Elevation Model(DEM)were used to construct the solid surface model.Steady-state Reynolds Averaged Navier-Stokes equations(RANS)with shear stress transport(SST)k-ωturbulence model were then applied to solve the flow field problems.Land-use changes were modeled implicitly by dividing the underlying surface into different areas and by applying corresponding aerodynamic roughness lengths.Simulations were performed by using cases with different city areas and building heights.Results show that the selected model could capture the surface roughness changes and could adjust wind profile over a large area.Wind profiles varied over the greenfield to the north and over the Gobi land to the east of the spring.Therefore,different wind speed reduction effects were observed from various city construction scenarios.The current city design would lead to about 2 m/s of wind speed reduction at the downwind city edge and about 1 m/s of wind speed reduction at the north of the spring at 35-m height.Reducing the city height in the north greenfield area could efficiently eliminate the negative effects of wind spee.By contrast,restricting the city area worked better in the eastern Gobi area compared with other parts of the study area.Wind speed reduction in areas near the spring could be limited to 0.1 m/s by combining these two abatement strategies.The CFD method could be applied to simulate the wind environment affected by other land-use changes over a large terrain.

Survey on Task Scheduling Optimization Strategy under Multi-Cloud Environment

Cloud computing technology is favored by users because of its strong computing power and convenient services.At the same time,scheduling performance has an extremely efficient impact on promoting carbon neutrality.Currently,scheduling research in the multi-cloud environment aims to address the challenges brought by business demands to cloud data centers during peak hours.Therefore,the scheduling problem has promising application prospects under themulti-cloud environment.This paper points out that the currently studied scheduling problems in the multi-cloud environment mainly include independent task scheduling and workflow task scheduling based on the dependencies between tasks.This paper reviews the concepts,types,objectives,advantages,challenges,and research status of task scheduling in the multi-cloud environment.Task scheduling strategies proposed in the existing related references are analyzed,discussed,and summarized,including research motivation,optimization algorithm,and related objectives.Finally,the research status of the two kinds of task scheduling is compared,and several future important research directions of multi-cloud task scheduling are proposed.

Optimal edge-cloud collaboration based strategies for minimizing valid latency of railway environment monitoring system

Response speed is vital for the railway environment monitoring system,especially for the sudden-onset disasters.The edge-cloud collaboration scheme is proved efficient to reduce the latency.However,the data characteristics and communication demand of the tasks in the railway environment monitoring system are all different and changeable,and the latency contribution of each task to the system is discrepant.Hence,two valid latency minimization strategies based on the edge-cloud collaboration scheme is developed in this paper.First,the processing resources are allocated to the tasks based on the priorities,and the tasks are processed parallly with the allocated resources to minimize the system valid latency.Furthermore,considering the differences in the data volume of the tasks,which will induce the waste of the resources for the tasks finished in advance.Thus,the tasks with similar priorities are graded into the same group,and the serial and parallel processing strategies are performed intra-group and inter-group simultaneously.Compared with the other four strategies in four railway monitoring scenarios,the proposed strategies proved latency efficiency to the high-priority tasks,and the system valid latency is reduced synchronously.The performance of the railway environment monitoring system in security and efficiency will be promoted greatly with the proposed scheme and strategies.

Computer-Vision Based Object Detection and Recognition for Service Robot in Indoor Environment

The near future has been envisioned as a collaboration of humans with mobile robots to help in the day-to-day tasks.In this paper,we present a viable approach for a real-time computer vision based object detection and recognition for efficient indoor navigation of a mobile robot.The mobile robotic systems are utilized mainly for home assistance,emergency services and surveillance,in which critical action needs to be taken within a fraction of second or real-time.The object detection and recognition is enhanced with utilization of the proposed algorithm based on the modification of You Look Only Once(YOLO)algorithm,with lesser computational requirements and relatively smaller weight size of the network structure.The proposed computer-vision based algorithm has been compared with the other conventional object detection/recognition algorithms,in terms of mean Average Precision(mAP)score,mean inference time,weight size and false positive percentage.The presented framework also makes use of the result of efficient object detection/recognition,to aid the mobile robot navigate in an indoor environment with the utilization of the results produced by the proposed algorithm.The presented framework can be further utilized for a wide variety of applications involving indoor navigation robots for different services.

A Compute Environment of ABC95 Array Computer Based on Multi-FPGA Chip

ABC95 array computer is a multi function network’s computer based on FPGA technology, The multi function network supports processors conflict free access data from memory and supports processors access data from processors based on enhanced MESH network. ABC95 instruction’s system includes control instructions, scalar instructions, vectors instructions. Mostly net work instructions are introduced. A programming environment of ABC95 array computer assemble language is designed. A programming environment of ABC95 array computer for VC++ is advanced. It includes load function of ABC95 array computer program and data, store function, run function and so on. Specially, The data type of ABC95 array computer conflict free access is defined. The results show that these technologies can develop programmer of ABC95 array computer effectively.

A Computational Model for Pedestrian Level Wind Environment Around Tall Buildings

A computational model has been developed for the simulation of pedestrian level wind environment around tall buildings by coupling the numerical simulation of the full scale site and meteorological station materials. In the first step, the hybrid/mixed finite element method is employed to solve the two dimensional Navier Stokes equation for the flow field around tall buildings, in view of the influence of fluctuating wind, the flow field is revised with the effective wind velocity. The velocity ratio is defined in order to relate numerical wind velocity to oncoming reference wind velocity. In the second step, the frequency occurred discomfort wind velocity as a suitable criterion is calculated by use of the coupling between the numerical wind velocity and the wind velocity at the nearest meteorological station. The prediction accuracy of the wind environment simulation by use of the computation model will be discussed. Using the available wind data at the nearest meteorological station as well as the established criteria of wind discomfort, the frequency of wind discomfort can be predicted. A numerical example is given to illustrate the application of the proposed method.

Computational fluid dynamics simulation of formaldehyde emission characteristics and its experimental validation in environment chamber

We investigated the effect of supply air rate and temperature on formaldehyde emission characteristics in an environment chamber.A three-dimensional computational fluid dynamics(CFD) chamber model for simulating formaldehyde emission in twelve different cases was developed for obtaining formaldehyde concentration by the area-weighted average method.Laboratory experiments were conducted in an environment chamber to validate the simulation results of twelve different cases and the formaldehyde concentration was measured by continuous sampling.The results show that there was good agreement between the model prediction and the experimental values within 4.3 difference for each case.The CFD simulation results varied in the range from 0.21 mg/m3 to 0.94 mg/m3,and the measuring results in the range from 0.17 mg/m3 to 0.87 mg/m3.The variation trend of formaldehyde concentration with supply air rate and temperature variation for CFD simulation and experiment measuring was consistent.With the existence of steady formaldehyde emission sources,formaldehyde concentration generally increased with the increase of temperature,and it decreased with the increase of air supply rate.We also provided some reasonable suggestions to reduce formaldehyde concentration and to improve indoor air quality for newly decorated rooms.

Intelligent Control of Cabin Environment Using Computational Fluid Dynamics for Intelligent Manufacturing

An efficient and versatile intelligent algorithm is developed for the control of the cabin environment of wind power generators.The method can be used to monitor and solve wind power generation problems at the same time.It also provides several advantages with respect to other traditional methods which imply significant workload and maintenance personnel.The functional requirements of the intelligent control system are analyzed,and a control algorithm for the stepping motor is selected and evaluated.Through the comparative analysis of the active power and internal temperature curve for three kinds of output power of the prototype,it is proved that the environmental intelligent control system greatly improves the operation efficiency,solves typical problems in the ventilator room environment,and provides a solid theoretical basis for further research in this field.

Research on College English Teaching Model under the Computer Environment

The growing update of computer and global technology provides the raw energy for college English teaching to start a revolution and development. How to deal with the teaching methods by using computer network to build a pluralistic system of interactive teaching for college English curriculum is a serious problem. This paper combines the characteristics of college English teaching, exploring the teaching ways of teaching mode and multi-interaction network of college English. Besides, it also reviews the evidence which is based on independent learning theory and several learning models, analyses the relationship between the advantages of computer network teaching and learning ability of students and enhances the benefits between teaching in practice and computer networks teaching. According to the research and survey of the College English Teaching Model of a University, it validated the role in promoting new teaching model to improve students’ self-learning ability.

Recent developments in computer assisted rehabilitation environments

Computer Assisted Rehabilitation Environment(CAREN) is a system that integrates a training platform(motion base), a virtual environment, a sensor system(motion capture) and D-flow software. It is useful for both diagnostic and therapeutic use. The human gait pattern can be impaired due to disease, trauma or natural decline. Gait analysis is a useful tool to identify impaired gait patterns. Traditional gait analysis is a very time consuming process and therefore only used in exceptional cases. With new systems a quick and extensive analysis is possible and provides useful tools for therapeutic purposes. The range of systems will be described in this paper, highlighting both their diagnostic use and the therapeutic possibilities. Because wounded warriors often have an impaired gait due to amputations or other extremity trauma, these systems are very useful for military rehabilitative efforts. Additionally, the virtual reality environment creates a very challenging situation for the patient, enhancing their rehabilitation experience. For that reason several Armed Forces have these systems already in use. The most recent experiences will be discussed; including new developments both in the extension of the range of systems and the improvement and adaptation of the software. A new and promising development, the use of CAREN in a special application for patients with posttraumatic stress disorder(PTSD), will also be reviewed.

Computer support system for residential environment evaluation for citizen participation

Though the method of citizen participation in urban planning is quite well established, for a specific segment of residential environment, however, existing participation system has not coped adequately with the issue. The specific residential environment has detailed aspects that need positive and high level involvement of the citizens in participating in all stages and every field of the plan. One of the best and systematic methods to obtain a more involved citizen is through a citizen workshop. To get a more “educated” citizen who participates in the workshop, a special session to inform the citizen on what was previously gathered through a survey was revealed to be prerequisite before the workshop. The computer support system is one of the best tools for this purpose. This paper describes the development of the computer support system for residential environment evaluation system, which is an essential tool to give more information to the citizens before their participation in public workshop. The significant contribution of this paper is the educational system framework involved in the workshop on the public participation system through computer support, especially for residential environment. The framework, development and application of the computer support system are described. The application of a workshop on the computer support system was commented on as very valuable and helpful by the audience as it resulted in greater benefit to have wider range of participation, and deeper level of citizen understanding.

Anonymity Effects and Implications in the Virtual Environment: From Crowd to Computer-Mediated Communication

Anonymity, an important feature of computer-mediated communication (CMC), is embedded in this new technology. With the penetration of the Internet in society, many daily activities involve online interactions. Anonymity affects both the task and social aspects of online communication including information exchange, decision making, and relationship development. This review examines the effects of anonymity on human behavior. It outlines how the prior literature has attempted to address this issue and how the Social Identity Deindividuation (SIDE) model has developed as an attempt to tackle this question. More importantly, it discusses a framework describing the multidimensions of anonymity in CMC [1], and subsequently raised five propositions inspired by this framework. Furthermore, using McLeod’s framework, this review evaluates SIDE studies with regard to their anonymity manipulations. This critique reveals possible future research directions for refining the SIDE model and better studying the effect of anonymity in virtual environment.

Impact of landscape on wind environment in residential area

Vegetation has positive effects on improving wind environment in residential areas which is important to the residents' pedestrian comfort. In order to reflect the impact of landscape on wind environment,a wind experiment was carried out in a typical residential area in Tsinghua University. Meanwhile,numerical simulation with reasonable plant models under the experimental boundary condition was held. By comparison between the experiment data and results of the simulation,wind direction of points in narrow passage and velocity of points in the first row facing the coming wind are almost accurate in simulation,but other points share big error percentage. The reason lies in the disturbing of wind model and settings of plant model. Moreover,by classifying measurement points according to relations between plants location and directions of coming wind,quantitative effects of vegetation are shown through simulations with plants and without plants. Plants directly facing the coming wind have most obvious function on decreasing the wind velocity,thus providing feasible scheme for vegetation design.

A Mobile Agent-Based Prototype of HeterogeneousDistributed Virtual Environment Systems

Mobile agents provide a new method for the distributed computation. This paper presents the advantages of using mobile agents in a distributed virtual environment (DVE) system, and describes the architecture of heterogeneous computer's distributed virtual environment system (HCWES) designed to populate some mobile agents as well as stationary agents. Finally, the paper introduces how heterogeneous computer network communication is to be realized.