Event-based discrete-time multi-agent consensus over signed digraphs with communication delays

The ability to ensure the desired performance of the cooperative-antagonistic multi-agent networks (MANs) in the presence of communication constraints is an important task in many applications of real systems. In this paper, under the proposed event-triggered condition (ETC), different types of consensus are obtained under different network topology. We concentrates on the event-based bipartite consensus. It is shown that under the proposed ETC (i) the addressed cooperative-antagonistic network with arbitrary communication delays reaches bipartite consensus provided that the network is balanced; (ii) the network model reaches zero if the network is unbalanced. Further, to avoid the continuously verifying the triggering condition, a self-triggered algorithm is proposed for realizing the bipartite consensus of the network model. A numerical example is given to illustrate the effectiveness of the theoretical results.     

Varieties of innovation and business survival: Does pursuit of incremental or far-ranging innovation make manufacturing establishments more resilient?

The transition from an industrial economy to an innovation economy poses two critical questions for the manufacturing sector in advanced countries. First, given the diffusion of modern manufacturing practices around the world, what level of innovation (incremental, more far-ranging, or radical) is most likely to support a resilient domestic manufacturing sector? Second, are assumed differences in the innovative capacity across space likely to hasten the decline of rural manufacturing? To answer these questions this research combines comprehensive measures of self-reported innovation able to reliably differentiate incremental and more far-ranging innovation with establishment-level data able to examine the geographical distribution of these different innovation strategies. The data used for the analysis includes a two-period panel of manufacturing establishments surveyed in 1996 and 2013 with annual employment data indicating survival in the intervening years. Our findings suggest that long-surviving manufacturing plants overwhelmingly gravitate away from non-innovation strategies toward incremental or more far-ranging innovation orientations. A survival advantage of far-ranging innovation over incremental innovation is observed for standalone firms. We do not identify a difference in the innovation orientations of rural and urban manufacturing establishments.     

Modification of Mikhailov stability criterion for fractional commensurate order systems

In this paper we present the modification of the Mikhailov stability criterion for linear fractional commensurate order systems. The modification consists in determining the appropriate measure for the total argument change depending on the highest fractional order ${\alpha }_n=n\alpha$ of the system and not only on the integer n as stated in the literature. The validity of the result is illustrated by means of several examples.     

Predictive ability of the medicine ball chest throw and vertical jump tests for determining muscular strength and power in adolescents

This study examined the predictive ability of the medicine ball chest throw and vertical jump for muscular strength and power in adolescents. One hundred and ninety adolescents participated in this study. Participants performed trials of the medicine ball chest throw and vertical jump, with vertical jump peak power calculated via an estimation equation. One-repetition maximum and peak power for the chest press and leg press were assessed using pneumatic exercise machines. The medicine ball chest throw strongly correlated with chest press one-repetition maximum and peak power, while the vertical jump peak power strongly correlated with leg press one-repetition maximum and peak power. The predictive ability of medicine ball chest throw was better than vertical jump peak power for muscular strength and power when controlling for sex, age, height, weight, and maturation, and was not affected by involvement in sports. Results show good predictive ability of the medicine ball chest throw for muscular strength and power in adolescents, while predictable ability of vertical jump peak power is weakened when other factors are taken into account.     

‘The East’ strikes back. Ultras Dynamo,hyper-stylization,and regimes of truth

Abstract

This case study deals with Ultras Dynamo, the leading group in the active fan scene of Eastern German (the term Eastern Germany is used within this paper to refer to the territory on which the GDR existed from 1949 to 1990; it entails the federal states Brandenburg, Mecklenburg-Vorpommern, Sachsen, Sachsen-Anhalt, Thuringia and the eastern part of Berlin) side SG Dynamo Dresden (throughout the paper, the club’s full name ‘Sportgemeinschaft Dynamo Dresden’ will be shortened using either Dynamo Dresden or simply Dynamo. Among the fans, the club is mostly called SGD (abbreviation of Sport[G]emeinschaft Dynamo) which is also used on flags, banners and in fan chants). The paper analyses styles of self-representation of the active fan scene at Dynamo and critically analyses the claim made by the group to being apolitical. The process of collective identity construction is linked to media images of the group and a ‘regime of truth’ is identified: a self-sustaining and interdependent cycle which overarches the process of image- and identity-construction at Dynamo Dresden and which can be traced back to processes of labelling, stigmatization and secondary deviance.     

Physiological implications of preparing for a natural male bodybuilding competition

This study aimed to describe the body composition and physiological changes which take place during the in-season and recovery periods of a group of natural bodybuilders. Natural male bodybuilders (n?=?9) were assessed 16 (PRE16), 8 (PRE8), and 1 (PRE1) week(s) before, and 4 (POST4) weeks after a bodybuilding competition. Assessments included body composition, resting metabolic rate (RMR), serum hormones, and 7-day weighed food and training diaries. Change in parameters was assessed using repeated-measures analysis of variance. Dietary protein intake remained high throughout the study period (2.8–3.1?g?kg^?1?d^?1). Fat mass (FM) was significantly reduced from PRE16 to PRE1 (8.8?±?3.1 vs. 5.3?±?2.4?kg, P?.01). There was a small decrease in lean mass (LM) from PRE8 to PRE1 (71.8?±?9.1 vs. 70.9?±?9.1?kg, P?P?>?.05). Large reductions in total and free testosterone (16.4?±?4.4 vs. 10.1?±?3.6?nmol?L^?1, P?. 116.8?±?76.9?pmol?L^?1, P?. 19.9?±?7.6?nmol?L^?1, P?. 72.5?±?8.5?kg, P?. 25.4?±?9.3?nmol?L^?1, P?相似文献   

Assessment of passive drag in swimming by numerical simulation and analytical procedure

The aim was to compare the passive drag-gliding underwater by a numerical simulation and an analytical procedure. An Olympic swimmer was scanned by computer tomography and modelled gliding at a 0.75-m depth in the streamlined position. Steady-state computer fluid dynamics (CFD) analyses were performed on Fluent. A set of analytical procedures was selected concurrently. Friction drag (D_f), pressure drag (D_pr), total passive drag force (D_f+pr) and drag coefficient (C_D) were computed between 1.3 and 2.5 m · s^?1 by both techniques. D_f+pr ranged from 45.44 to 144.06 N with CFD, from 46.03 to 167.06 N with the analytical procedure (differences: from 1.28% to 13.77%). C_D ranged between 0.698 and 0.622 by CFD, 0.657 and 0.644 by analytical procedures (differences: 0.40–6.30%). Linear regression models showed a very high association for D_f+pr plotted in absolute values (R² = 0.98) and after log–log transformation (R² = 0.99). The C_D also obtained a very high adjustment for both absolute (R² = 0.97) and log–log plots (R² = 0.97). The bias for the D_f+pr was 8.37 N and 0.076 N after logarithmic transformation. D_f represented between 15.97% and 18.82% of the D_f+pr by the CFD, 14.66% and 16.21% by the analytical procedures. Therefore, despite the bias, analytical procedures offer a feasible way of gathering insight on one’s hydrodynamics characteristics.     

Does school physical education really contribute to accelerometer-measured daily physical activity and non sedentary behaviour in high school students?

Physical education has been highlighted as an important environment for physical activity promotion, however, to our knowledge there are no previous studies examining the contribution of physical education to daily accelerometer-measured physical activity and non sedentary behaviour. The purpose was to compare the accelerometer-measured physical activity and sedentary behaviour between physical education, non-physical education and weekend days in adolescents. Of the 394 students from a Spanish high school that were invited to participate, 158 students (83 boys and 75 girls) aged 13–16 years were analyzed (wear time ≥ 600 min). Participants’ physical activity and sedentary behaviour were objectively-measured by GT3X+ accelerometers during physical education (one session), non-physical education and weekend days. Results indicated that overall adolescents had statistically significant greater physical activity levels and lower values of sedentary behaviour on physical education days than on non-physical education and weekend days (e.g., moderate-to-vigorous physical activity = 71, 54 and 57 min; sedentary = 710, 740 and 723 min) (p < 0.05). Physical education contributes significantly to reducing students’ daily physical inactivity and sedentary behaviour. Increasing the number of physical education classes seems to be an effective strategy to reduce the high current prevalence of physical inactivity and sedentary behaviour in adolescence.     

Visuelle Bewegungskontrolle geführter Kraftübungen bei jungen Erwachsenen und Senioren

In the context of strength training in rehabilitation, visual movement control can be helpful to ensure correct movements. However, there are only a few studies that deal with the effectiveness of feedback during resistance exercises. To investigate the effect of feedback during guided exercise, 18 young adults (28.8?±?5.5 years) and 12 senior citizens (67.9?±?4.1 years) were tested. Subjects performed shoulder press exercises (3 sets, 15 repetitions) with and without visual movement control in a randomized order. On day 1, the subjects trained without load, and on day 2 they trained at 50% of their single repetition maximum. Joint articulation at the elbow was recorded using elbow extension and flexion. Autocorrelation was used to determine the reproducibility of movements. Subjects achieved better reproducibility of the movement with feedback than without (χ²?=?19.73; p?<?0.001). There was no effect of the load on motion accuracy (p?>?0.05), but the age group showed a significant effect (χ²?=?6.00; p?=?0.014). The younger group shows a higher degree of movement accuracy. In summary, visual movement control is useful in guided exercises to control movement execution. In clinical setting, this may be a way to control the motion performance of guided strength exercises and to ensure purposeful muscle work. Further studies should clarify the effect of visual feedback on the movement quality in unguided strength exercises.