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Existing studies on human activity recognition using inertial sensors mainly discuss single activities. However, human activities are rather concurrent. A person could be walking while brushing their teeth or lying while making a call. The purpose of this paper is to explore an effective way to recognize concurrent activities.

Concurrent activities usually involve behaviors from different parts of the body, which are mainly dominated by the lower limbs and upper body. For this reason, a hierarchical method based on artificial neural networks (ANNs) is proposed to classify them. At the lower level, the state of the lower limbs to which a concurrent activity belongs is firstly recognized by means of one ANN using simple features. Then, the upper-level systems further distinguish between the upper limb movements and infer specific concurrent activity using features processed by the principle component analysis.

An experiment is conducted to collect realistic data from five sensor nodes placed on subjects’ wrist, arm, thigh, ankle and chest. Experimental results indicate that the proposed hierarchical method can distinguish between 14 concurrent activities with a high classification rate of 92.6 per cent, which significantly outperforms the single-level recognition method.

In the future, the research may play an important role in many ways such as daily behavior monitoring, smart assisted living, postoperative rehabilitation and eldercare support.

To provide more accurate information on people’s behaviors, human concurrent activities are discussed and effectively recognized by using a hierarchical method.

In sensor-based activity recognition, most of the previous studies focused on single activities such as body posture, ambulation and simple daily activities. Few works have been done to analyze complex concurrent activities. The purpose of this paper is to use a statistical modeling approach to classify them.

In this study, the recognition problem of concurrent activities is explored with the framework of parallel hidden Markov model (PHMM), where two basic HMMs are used to model the upper limb movements and lower limb states, respectively. Statistical time-domain and frequency-domain features are extracted, and then processed by the principal component analysis method for classification. To recognize specific concurrent activities, PHMM merges the information (by combining probabilities) from both channels to make the final decision.

Four studies are investigated to validate the effectiveness of the proposed method. The results show that PHMM can classify 12 daily concurrent activities with an average recognition rate of 93.2 per cent, which is superior to regular HMM and several single-frame classification approaches.

A statistical modeling approach based on PHMM is investigated, and it proved to be effective in concurrent activity recognition. This might provide more accurate feedback on people’s behaviors.

The research may be significant in the field of pervasive healthcare, supporting a variety of practical applications such as elderly care, ambient assisted living and remote monitoring.

Given the less mature homeschooling ecosystem in China, together with the similarity of purpose, the current study examined the lived experiences of curricular choice making in the USA and China and categories of respective families (homeschools), as a way of understanding curricular flexibility. In addressing these features, based on an updated model of curricular flexibility as it applies to homeschooling, the authors examined the aspects of who, what, when, where and how to see if this context offers new light. The authors then consider ways in which the model can be further updated for greater analytical clarity and accuracy. The purpose of this paper is to address these issues.

A descriptive case study was conducted in the Xi'an city of China and the Seattle metropolitan area of the USA. A survey and two rounds of semi-structured interview data were collected from ten homeschooling families in both contexts.

The study found families’ adjusted curricula for different motives, as they navigated differing societal contexts, and curricular flexibility in homeschooling contexts was theorized as standardization and structuring strategies and social dimensions, and family preference patterns were identified. Chinese homeschooling families had comparatively less variety of available resources and freedom to homeschools compared to American counterparts, and they operated with the awareness of a standard national curriculum and its social implications.

This study elaborates on a little-discussed topic – the overall curriculum of each homeschool and motives influencing changing curricular choices during the process of homeschooling. And it is the first paper to use the model to explicitly define curricular flexibility in the homeschooling context, thus extending the existing theoretical discussion of curricular flexibility.

The purpose of this paper is to introduce an interval finite element method (IFEM) to simulate the temperature field of mass concrete under multiple influence uncertainties e.g. environmental temperature, material properties, pouring construction and pipe cooling.

Uncertainties of the significant factors such as the ambient temperature, the adiabatic temperature rise, the placing temperature and the pipe cooling are comprehensively studied and represented as the interval numbers. Then, an IFEM equation is derived and a method for obtaining interval results based on monotonicity is also presented. To verify the proposed method, a non-adiabatic temperature rise test was carried out and subsequently simulated with the method. An excellent agreement is achieved between the simulation results and the monitoring data.

An IFEM method is proposed and a non-adiabatic temperature rise test is simulated to verify the method. The interval results are discussed and compared with monitoring data. The proposed method is found to be feasible and effective.

Compared with the traditional finite element methods, the proposed method taking the uncertainty of various factors into account and it will be helpful for engineers to gain a better understanding of the real condition.

This paper aims to describe the design of a multi-degree of freedom (DOF) prosthetic hand prototype implementing postural synergy mechanically, which is actuated by two motors via a transmission unit, and is controlled using surface electromyography (sEMG) signal.

First, an anthropomorphic robotic hand is designed to imitate the human hand. The robotic hand has 18 DOF, 12 of which are actively driven by Bowden cables. Next, a set of different grasp modes are performed on a “full actuation” robotic hand, and principal component analysis (PCA) method is used to extract the first two postural synergies. Then, they are used to design a differential pulley-based transmission unit using two independent inputs to drive 12 output tendons. Finally, two control signals extracted from six channels of sEMG signals are used to proportionally control the two motors for achieving hand posture synthesis.

Using a differential pulley-based mechanical transmission unit to implement the synthesis of the first two postural synergies can make the prosthetic hand achieve different grasps by two motors, such as power, precision and lateral grasps. It is also feasible to control this “two actuation” prosthetic hand by relating the two-dimensional sEMG inputs with the first two postural synergies.

Mechanical implantation of postural synergies reduces the number of independent actuators without sacrificing the prosthetic hand’s versatility and simplifies its controller. Two-dimensional control extracted from sEMG is mapped into the combination coefficients of postural synergy synthesis. It shows potential application in the practical prosthetic hand.

The purpose of this paper is to explore an indigenous innovation phenomenon – entitled the Shanzhai phenomenon – which has emerged in the Chinese mobile phone industry, and to understand its value creation network and operational mechanism, as well as to recognize its policy implications in regional and industrial developments.

Although the Shanzhai phenomenon emerged from the end of 2008, detailed understanding of its systems and operational mechanism is still very limited, partly because of its secrecy and dynamics in the value chain operations. Based on characteristics of the Shaizhai phenomenon, the paper focuses on three levels of the phenomenon – regional historical, regional industrial specific, and typical Shanzhai mobile phone project levels – to pursue a comprehensive understanding of the Shanzhai system and its emerging environments. At the regional and industrial level, the combined approaches of interview and secondary data collection is adopted. At the Shanzhai project level, a case study approach is conducted by focusing on the project and its whole value chain, from the idea creation towards detailed product design, production and integration, as well as its distribution.

Chinese government has called for indigenous innovation to upgrade Chinese manufacturing capability and value creation as well as appropriation. Based on the fast growth of the Chinese indigenous mobile phone industry in the last two years, the Shanzhai manufacturing system is recognized as a new positive alternative way for Chinese manufacturing companies to achieve this aim. Behind the Shanzhai phenomenon, there is a strong globally specialized and collaborated network enabling the down‐stream Chinese small‐ and medium‐sized mobile phone companies to very quickly respond to customers' demands or lead the demands. This new type of alternative innovation system is transforming unaffordable luxury goods into affordable for normal consumers. Because of its mass volume and involvement, however, government policies to harness the energy and development direction become essential.

This research is just a very early stage of preliminary observation. From the methodology perspective, it provides background information about Shanzhai phenomenon and an in‐depth case study about a Shanzhai project. Comprehensive understandings of the Shanzhai phenomenon in terms of its behaviours, systems constructs and patterns, trajectories in the future and implications for policies will be achieved only at a much later date.

ShanZhai manufacturing might be one possible alternative innovative paradigm in some sectors of China.

This is the first academic research paper to offer relatively comprehensive and systematic observations about the emerging ShanZhai manufacturing system in the largest developing country.

The smoothness of the high-speed railway (HSR) on the bridge may exceed the allowable standard when an earthquake causes vibrations for HSR bridges, which may threaten the safety of running trains. Indeed, few studies have evaluated the exceeding probability of rail displacement exceeding the allowable standard. The purposes of this article are to provide a method for investigating the exceeding probability of the rail displacement of HSRs under seismic excitation and to calculate the exceeding probability.

In order to investigate the exceeding probability of the rail displacement under different seismic excitations, the workflow of analyzing the smoothness of the rail based on incremental dynamic analysis (IDA) is proposed, and the intensity measure and limit state for the exceeding probability analysis of HSRs are defined. Then a finite element model (FEM) of an assumed HSR track-bridge system is constructed, which comprises a five-span simply-supported girder bridge supporting a finite length CRTS II ballastless track. Under different seismic excitations, the seismic displacement response of the rail is calculated; the character of the rail displacement is analyzed; and the exceeding probability of the rail vertical displacement exceeding the allowable standard (2mm) is investigated.

The results show that: (1) The bridge-abutment joint position may form a step-like under seismic excitation, threatening the running safety of high-speed trains under seismic excitations, and the rail displacements at mid-span positions are bigger than that at other positions on the bridge. (2) The exceeding probability of rail displacement is up to about 44% when PGA = 0.01g, which is the level-five risk probability and can be described as 'very likely to happen'. (3) The exceeding probability of the rail at the mid-span positions is bigger than that above other positions of the bridge, and the mid-span positions of the track-bridge system above the bridge may be the most hazardous area for the running safety of trains under seismic excitation when high-speed trains run on bridges.

The work extends the seismic hazardous analysis of HSRs and would lead to a better understanding of the exceeding probability for the rail of HSRs under seismic excitations and better references for the alert of the HSR operation.

The microseismic monitoring technique has great advantages on identifying the location, extent and the mechanism of damage process occurring in rock mass. This study aims to analyze distribution characteristics and the evolution law of excavation damage zone of surrounding rock based on microseismic monitoring data.

In situ test using microseismic monitoring technique is carried out in the large-span transition tunnel of Badaling Great Wall Station of Beijing-Zhangjiakou high-speed railway. An intelligent microseismic monitoring system is built with symmetry monitoring point layout both on the mountain surface and inside the tunnel to achieve three-dimensional and all-round monitoring results.

Microseismic events can be divided into high density area, medium density area and low density area according to the density distribution of microseismic events. The positions where the cumulative distribution frequencies of microseismic events are 60 and 80% are identified as the boundaries between high and medium density areas and between medium and low density areas, respectively. The high density area of microseismic events is regarded as the high excavation damage zone of surrounding rock, which is affected by the grade of surrounding rock and the span of tunnel. The prediction formulas for the depth of high excavation damage zone of surrounding rock at different tunnel positions are given considering these two parameters. The scale of the average moment magnitude parameters of microseismic events is adopted to describe the damage degree of surrounding rock. The strong positive correlation and multistage characteristics between the depth of excavation damage zone and deformation of surrounding rock are revealed. Based on the depth of high excavation damage zone of surrounding rock, the prestressed anchor cable (rod) is designed, and the safety of anchor cable (rod) design parameters is verified by the deformation results of surrounding rock.

The research provides a new method to predict the surrounding rock damage zone of large-span tunnel and also provides a reference basis for design parameters of prestressed anchor cable (rod).