Inverted Modelling:An Effective Way to Support Motion Planning of Legged Mobile Robots

This paper presents an effective way to support motion planning of legged mobile robots—Inverted Modelling,based on the equivalent metamorphic mechanism concept.The difference from the previous research is that we herein invert the equivalent parallel mechanism.Assuming the leg mechanisms are hybrid links,the body of robot being considered as fixed platform,and ground as moving platform.The motion performance is transformed and measured in the body frame.Terrain and joint limits are used as input parameters to the model,resulting in the representation which is independent of terrains and particular poses in Inverted Modelling.Hence,it can universally be applied to any kind of legged robots as global motion performance framework.Several performance measurements using Inverted Modelling are presented and used in motion performance evaluation.According to the requirements of actual work like motion continuity and stability,motion planning of legged robot can be achieved using different measurements on different terrains.Two cases studies present the simulations of quadruped and hexapod robots walking on rugged roads.The results verify the correctness and effectiveness of the proposed method.

Study on Influencing Factors of Mental Health of Mobile Young White-Collar Workers in China

Mobile young white-collar workers not only have the characteristics of mobile young people,but also have the characteristics of general white-collar workers.Under the influence of both,their mental health may be suffering from“double disadvantage”.So,based on an ecological model of the stress process,this paper tries to use the data of the questionnaire on the mental health of mobile young white-collar workers in Zhejiang Province to explore the influence of some factors in the middle workplace and residence place on the mental health of micro individuals.The results show that:(1)The working environment with high control and low freedom and the workplace discrimination against the mobile status will have a negative impact on the mental health of mobile young white-collar workers;(2)Financial anxiety in daily life will lead to a decline in the mental health level of mobile young white-collar workers;(3)Good organizational support and neighborhood social relations can significantly relieve life pressure,so as to effectively improve the mental health of mobile young white-collar workers.It can be seen that we also need to pay more attention to the mental health of mobile young white-collar workers in order to improve their situation.

RPL-Based IoT Networks under Decreased Rank Attack:Performance Analysis in Static and Mobile Environments

The RPL(IPv6 Routing Protocol for Low-Power and Lossy Networks)protocol is essential for efficient communi-cation within the Internet of Things(IoT)ecosystem.Despite its significance,RPL’s susceptibility to attacks remains a concern.This paper presents a comprehensive simulation-based analysis of the RPL protocol’s vulnerability to the decreased rank attack in both static andmobilenetwork environments.We employ the Random Direction Mobility Model(RDM)for mobile scenarios within the Cooja simulator.Our systematic evaluation focuses on critical performance metrics,including Packet Delivery Ratio(PDR),Average End to End Delay(AE2ED),throughput,Expected Transmission Count(ETX),and Average Power Consumption(APC).Our findings illuminate the disruptive impact of this attack on the routing hierarchy,resulting in decreased PDR and throughput,increased AE2ED,ETX,and APC.These results underscore the urgent need for robust security measures to protect RPL-based IoT networks.Furthermore,our study emphasizes the exacerbated impact of the attack in mobile scenarios,highlighting the evolving security requirements of IoT networks.

A multidimensional and hierarchical model of library mobile service quality

Purpose:Based on the understanding of the characteristics of mobile services(m-services)provided by libraries,we attempt to develop a multidimensional and hierarchical model and a specifically designed measurement scale for the assessment of libraries' m-service quality.Design/methodology/approach:The research has been conducted sequentially in two stages.At the first stage,a multidimensional and hierarchical model of library m-service quality and a measurement scale are developed through literature review and focus group interviews.At the second stage the model is tested using partial disaggregation technique for an analysis of the data collected from over 400 library users in 3 Chinese universities.Findings:The proposed model is shown to fit the data well.The empirical analysis provides strong support for the model,which includes 4 dimensions(service environment,service interaction,information control and service effect) and 12 corresponding sub-dimensions.Research limitations:The sample size needs to be enlarged and the user types need to be expanded to make the sample more representative.Practical implications:The study provides a conceptual framework and measurement tool that can help library managers understand the users' needs in the context of mobile network environment,and boost their libraries' competitiveness by carrying out better services to meet the user demands.Originality/value:The proposed model and measurement scale specifically designed for the assessment of libraries' m-service quality fully reflect the hierarchical structure of libraries' m-service quality.In addition,by using partial disaggregation technique for model testing,we believe our research can serve as a practical reference to those engaged in the development and examination of a multidimensional and hierarchical model.

A Model of Mobile P2P Network Architecture based on Agent

A model of mobile peer to peer (P2P) network architecture based on agent for mobile value-added services is proposed in this paper. By using this model, wireless devices can build a P2P network dynamically, and then they can access and transmit information peer to peer. An ontologybased semantic information description method is also proposed for the mobile wireless devices. The merit of this method is to enhance search efficiency. Moreover, a small system, called CellChat, has been implemented based on this model in the lab environment. Experimental results are provided to show that the benefi ts of the proposed method. This method will become an effective solution for mobile value-added services in 3G network.

Space station short-term mission planning using ontology modelling and time iteration

This paper studies the problem of the space station short-term mission planning, which aims to allocate the executing time of missions effectively, schedule the corresponding resources reasonably and arrange the time of the astronauts properly. A domain model is developed by using the ontology theory to describe the concepts, constraints and relations of the planning domain formally, abstractly and normatively. A method based on time iteration is adopted to solve the short-term planning problem. Meanwhile, the resolving strategies are proposed to resolve different kinds of conflicts induced by the constraints of power, heat, resource, astronaut and relationship. The proposed approach is evaluated in a test case with fifteen missions, thirteen resources and three astronauts. The results show that the developed domain ontology model is reasonable, and the time iteration method using the proposed resolving strategies can successfully obtain the plan satisfying all considered constraints.

The Clinical Study of a New Management Model Using Mobile Health for Senile Hypertension

Objective: To evaluate a new management model using mobile health for senile hypertension. Methods: This medical service combined traditional medical treatment with Mobile Health. We use it to explore a new and effective model of elderly hypertension management and the most effective and lowest cost management crowd. According to the randomized controlled design of trial, 105 old hypertensive patients participated in the study voluntarily in the Qingdao Municipal Hospital were randomly divided into the experimental group (75 cases) and control group (30 cases). Experimental group is divided into geriatric specialist group (25 cases), general practitioner group (25 cases) and nurse group (25 cases). Blood pressure was administered in experimental (with the new model) and control groups (with the traditional model) for 2 months to compare their blood pressure and the decrease of them. Results: Blood pressure was compared between the two groups before and after administration. The systolic blood pressure (SBP) of experimental group is 162.44 ± 13.970 mmHg before administration. SBP of experimental group is 147.69 ± 13.509 mmHg after administration, the difference is statistically significant (P = 0.000). The diastolic blood pressure (DBP) of experimental group is 91.58 ± 10.822 mmHg before administration. DBP of experimental group is 84.64 ± 10.412 mmHg after administration, P = 0.003. SBP of control group is 159.93 ± 15.238 mmHg before administration. The systolic blood pressure of control group is 152.33 ± 14.115 (mmHg) after administration. P is 0.167 (P > 0.05). The difference was not statistically significant. DBP of control group is 94.73 ± 12.401 (mmHg) before administration. DBP of control group is 90.60 ± 11.115 (mmHg) after administration. P is 0.345 (P > 0.05). The difference was not statistically significant. The decrease of SBP of geriatric specialist group, general practitioner group and nurse group is 18.40 ± 11.764 mmHg, 14.47 ± 9.44 mmHg, 10.80 ± 6.026 mmHg. The difference was not statistically significant (P > 0.05). The decrease of DBP of geriatric specialist group, general practitioner group and nurse group is 9.33 ± 7.451 mmHg vs. 5.33 ± 6.287 mmHg vs. 6.13 ± 5.069 mmHg (P > 0.05). Conclusion: The new model is effective and it works well for controlling blood pressure of elderly hypertensive patients. Especially with the doctors and patients’ families, the management effect has been obviously improved. Medical interventions make the new model more scientific. The management of geriatric specialists, general practitioners and nurses is equally valid.

Dynamic modeling and simulation for nonholonomic welding mobile robot

Based on the Newton-Euler method, the dynamic behaviors of the left and right driving wheels and the robot body for the welding mobile robot were derived. In order to realize the combination control of body turning and slider adjustment, the dynamic behaviors of sliders were also investigated. As a result, a systematic and complete dynamic model for the welding mobile robot was constructed. In order to verify the effectiveness of the above model, a sliding mode tracking control method was proposed and simulated, the lateral error stabilizes between -0.2 mm and ＋0.2 mm, and the total distance of travel for the slider is consistently within 4-2 ram. The simulation results verify the effectiveness of the established dynamic model and also show that the seam tracking controller based on the dynamic model has excellent performance in terms of stability and robustness. Furthermore, the model is found to be very suitable for practical applications of the welding mobile robot.

STUDY AND COMPUTER SIMULATION OF AN ADAPTIVE STATISTIC MODEL FOR MOBILE COMMUNICATION CHANNEL

An adaptive statistic model for mobile communication channel is studied and simulated in this paper. According to the model parameters, an error sequence describing the long burst error characteristics of the mobile communication channel is generated on a computer. A test method using threshold technique is presented to verify the accuracy of the adaptive channel model.

The Application of Genetic Algorithms and Multidimensional Distinguishing Model in Forecasting and Evaluating Credits for Mobile Clients

To solve the arrearage problem that puzzled most of the mobile corporations, we propose an approach to forecast and evaluate the credits for mobile clients, devising a method that is of the coalescence of genetic algorithm and multidimensional distinguishing model. In the end of this paper, a result of a testing application in Zhuhai Branch, GMCC was provided. The precision of the forecasting and evaluation of the client’s credit is near 90%. This study is very significant to the mobile communication corporation at all levels. The popularization of the techniques and the result would produce great benefits of both society and economy.

Analysis of reflected signal of quad rotor UAV based on model fitting in mobile communication system

In view of the many scenes of unmanned aerial vehicle(UAV)detection,a third-party signal source is used to design a receiver to monitor the UAV.It is of great significance to understand the reflection of the signal illuminating the UAV.Taking the communication base station(BS)signal as the third-party signal source,and considering the complete transmission link,reflection changes and loss fading of the communication signal,this study conducts model fitting for irregular UAV targets,simplifying complex targets into a combination of simple targets.Furthermore,the influence of the dielectric constant of the target surface and the signal irradiation angle on the signal reflection is analyzed.The analysis shows that the simulation results of this model fitting method are consistent with the results of other literature,which provides theoretical support for the detection of low and slow small targets such as UAVs.

Using Box-Jenkins Models to Forecast Mobile Cellular Subscription

In this paper, the Box-Jenkins modelling procedure is used to determine an ARIMA model and go further to forecasting. The mobile cellular subscription data for the study were taken from the administrative data submitted to the Zambia Information and Communications Technology Authority (ZICTA) as quarterly returns by all three mobile network operators Airtel Zambia, MTN Zambia and Zamtel. The time series of annual figures for mobile cellular subscription for all mobile network operators is from 2000 to 2014 and has a total of 15 observations. Results show that the ARIMA (1, 2, 1) is an adequate model which best fits the mobile cellular subscription time series and is therefore suitable for forecasting subscription. The model predicts a gradual rise in mobile cellular subscription in the next 5 years, culminating to about 9.0% cumulative increase in 2019.

Three-stage Nonlinear Thermal Model for Microspeakers in Mobile Phones

Since microspeakers are widely used in mobile phones,high power is usually applied to obtain sufficient output sound pressure.However,the electric power is almost converted into heat,leading to the thermal problem in microspeakers.Compared with large loudspeaker,microspeakers are smaller and the under yoke is relatively closed,causing the heat transfer more complex.In this study,a three-stage nonlinear thermal model was proposed for analyzing the thermal behavior in microspeakers.The inside air is a buffer area between the voice coil and magnet,and modeled as a middle stage of the heat transfer.The forced convection is still significant in microspeakers while the eddy current can be ignored.In order to obtain the thermal parameters of the model,a corresponding parameter identification method was put forward.The basic linear parameters and forced convection parameters were all obtained by measuring and fitting the temperature curves of voice coil at different single tones.A series of experiments were conducted to verify the proposed model and parameter identification method,and the results showed good aggrement between the measured and predicted temperature curves for different input signals.The proposed model was valid and accurate,and may be helpful for the design and application of microspeakers.

Wideband Modeling of Land-Mobile-Satellite Channel in Built-Up Environment

This paper presents a propagation model for land-mobile-satellite (LMS) wideband radio channel in built-up environment. The model characterizes the behavior of the radio channel, under shadowing and multipath effects due to buildings, with variation of the elevation angle of the satellite. The wideband parameters (coherent bandwidth and time delay spreading) for LMS channel, in residential and urban environments, are computed. These parameters can be considered as a measure of the amount of ISI (inter-symbol interference) of the radio channel, which distorts the received signal and accordingly increases the bit error rate. The calculated values for these parameters using our model, show very good agreement with the corresponding measured ones, which accordingly shows the validity of the developed model for radio channel design in satellite mobile communication systems.

Lewin Behavior Model-Based Study on Influence Factors of Individuals to Mobile Service Demand

How to fmd main influence factors of individuals to mobile service demand is investiga- ted. The empirical research is conducted in the sample of high-value customers in China mobile market. Based on Lewin behavior model, this pa- per establishes factors-matrix from personal and environmental dimensions. Relationships among multiple factors are tested in the structural equa- tion model and their impacts on customers＇ de- mands are elaborated. Findings indicate that opera- tional convenience and business brand image have significant effects on sample users＇ demands. Fur- thermore, annual income, gender, occupation, the needs of access to information and the needs of enriching and improving social relationships are al- so important factors for high-value users. The re- suits may provide further insights into mobile service demand and the model can be popularized to other behavior researches.

Parameter Selection and Performance Analysis of Mobile Terminal Models Based on Unity3D

Mobile platform is now widely seen as a promising multimedia service with a favorable user group and market prospect. To study the influence of mobile terminal models on the quality of scene roaming, a parameter setting platform of mobile terminal models is established to select the parameter selection and performance index on different mobile platforms in this paper. This test platform is established based on model optimality principle, analyzing the performance curve of mobile terminals in different scene models and then deducing the external parameter of model establishment. Simulation results prove that the established test platform is able to analyze the parameter and performance matching list of a mobile terminal model.

Research on Blended Teaching Model in College English Based on Mobile Learning App

Mobile learning is the general trend of the times and the inevitable choice for the reform and development of college English teaching.This article attempts to use blended learning theory,mobile learning theory,and instructional design theory as a guide.In many English mobile learning apps,Superstar Learning Link is used as an example to design an online and offline blended teaching mode.It proposes thinking expansion and interaction in pre-class stage.Consolidation of input and outputoriented process are during class and evaluation and sublimation are made after class.The essay is aimed to break the boundaries between traditional teaching and mobile learning,combining synchronous learning with personalized learning in order to improve comprehensive levels of English.

Continuance intention to use the mobile interest-based community: An integrated theoretical model and empirical study

Purpose： This paper aims at an understanding of factors that influence the continuance intention to use mobile interest-based community applications, with a focus on the impacts of technology acceptance model （TAM） constructs and experiential value. Design/methodology/approach： Taking a hybrid model combining TAM and extended expectation confirmation model （ECM） as foundation, this study integrated experiential value into the research model. A survey method was adopted and the sample was constituted by 347 Chinese undergraduates who were experienced users of mobile interest-based community applications. Structural equation modeling was used to test the research model. Findings： Our findings suggest that 1） key determinants of user satisfaction with mobile interest-based community applications are confirmation, perceived usefulness （PU）, perceived ease of use （PEU） and experiential value. Both satisfaction and PU are directly correlated with continuance intention; 2） PU＇s impact on satisfaction and continuance intention has been confirmed again in this study. Although PEU has no direct impact on satisfaction and continuance intention, it may indirectly affect them via PU; 3） all the perceived experiential values （aesthetics, playfulness, service excellence and return on investment） have a positive influence on satisfaction. Research limitations： We did not examine the effects of individual user differences that may also be important for understanding satisfaction and continuance intention. Practical implications： The study findings can help service providers improve the use of mobile interest-based community applications. Originality/value： Our study contributes to a more systematic understanding of factors that influence continuous use of mobile interest-based community applications.

A New Aim-Points-Choosing Model for Attacking Mobile Missile Systems

A new aim-points-choosing model for attacking mobile missile systems in sector region is presented and realized in this paper. The model has the generality for attacking mobile target andis also useful for making an operational decision.

Analysis of reactive routing protocols for mobile ad hoc networks in Markov models

Mobile ad hoc networks （MANETs） have become a hot issue in the area of wireless networks for their non-infrastructure and mobile features. In this paper, a MANET is modeled so that the length of each link in the network is considered as a birthdeath process and the space is reused for n times in the flooding process, which is named as an n-spatiai reuse birth-death model （n-SRBDM）. We analyze the performance of the network under the dynamic source routing protocol （DSR） which is a famous reactive routing protocol. Some performance parameters of the route discovery are studied such as the probability distribution and the expectation of the flooding distance, the probability that a route is discovered by a query packet with a hop limit, the probability that a request packet finds a τ-time-valid route or a symmetric-valid route, and the average time needed to discover a valid route. For the route maintenance, some parameters are introduced and studied such as the average frequency of route recovery and the average time of a route to be valid. We compare the two models with spatial reuse and without spatial reuse by evaluating these parameters. It is shown that the spatial reuse model is much more effective in routing.