Functional impact of emotions on athletic performance: comparing the IZOF model and the directional perception approach

The aim of this study was to examine the impact of emotions on athletic performance within the frameworks of the Individual Zones of Optimal Functioning (IZOF) model and the directional perception approach. Intensity, functional impact, and hedonic tone of trait and state anxiety, self-confidence, idiosyncratic emotions, and bodily symptoms were assessed in high-level Italian swimmers and track and field athletes (N = 56). Three standards of performance (poor, average, and good), derived from retrospective self-ratings across one to three competitions (a total of 90 observations), were used as independent variables in the analysis of variance of intensity, intra-individual, and direction scores of anxiety, self-confidence, idiosyncratic emotions, and bodily symptoms. Subsequently, intra-individual scores were categorized as near to or distant from optimal/dysfunctional zones and entered as the independent variable in the analysis of direction scores. The results provided support for the predictions stemming from both the IZOF model and the directional approach, as well as help in interpreting direction of anxiety and other idiosyncratic emotions within the IZOF framework. Athletes tended to perceive emotional levels approximating an individual's optimal zone as facilitative-pleasant, and emotional levels approximating an individual's dysfunctional zone as debilitative-unpleasant.     

An exact formula for the maximum VCO sweep rate of a PLL

In many phase-locked loop (PLL) applications, the natural pull-in mechanism is too slow and unreliable, and it must be accelerated. By adding an externally-generated ramp to its control voltage input, the PLL voltage controlled oscillator (VCO) frequency can be swept towards the input reference frequency in an attempt to speed up the pull-in process. This popular acquisition aid has a significant limitation when it is used in a second-order, Type II PLL. If the applied ramp voltage has a slope magnitude greater than (alternatively, less than) some value R_m, the PLL state can (alternatively, cannot) sweep past the desired lock point, resulting in a phase lock failure (alternatively, success). In general, the maximum sweep rate magnitude R_m can be computed by using a numerical integration-and-search procedure that is described in the PLL literature. A special case exists for a second-order, Type II PLL that incorporates a triangular-characteristic phase detector (with logic-level binary input signals). For this case, it is possible to develop an exact, closed-form expression for R_m, the main result of this paper. For a range of loop parameters most often used in applications, R_m values are computed by using the exact formula, and these are used in two ways. First, they are used to validate the previously-mentioned numerical integration-and-search procedure. Second, they are compared to maximum sweep rate values computed for a PLL that utilizes a sinusoidal phase detector to show that the triangular-phase-detector PLL can be swept significantly faster than the sinusoidal-phase-detector loop.     

Decentralized continuous MRAC with local asymptotic sliding modes of nonlinear delayed interconnected systems

In this contribution, we develop continuous completely decentralized state-feedback adaptive controllers with sliding mode for a class of large-scale interconnected systems with nonlinear interconnections with unknown time-varying state delays. The novel contribution of this paper is that asymptotically exact tracking within the framework of completely decentralized direct continuous adaptive control is possible also for a class of nonlinear plants with matched interconnections and disturbances.     

Values, objectivity and credibility of scientists in a contentious natural resource debate

In contentious natural resource debates, the credibility of scientists is at risk. In this case study, citizens in contending communities and scientists in a forest management controversy constructed the scientists' credibility differently. Shared values and views of the nature of science and objectivity were primary factors for constructing scientists' credibility. Citizens who expected value-free, objective scientists to authenticate their knowledge were concerned about how the values of scientists on the opposite side affected research framing. Citizens who emphasized limited objectivity were less skeptical of scientists. Scientists acknowledged their values but defended their credibility in terms of professional standards, balance and resource constraints. In short, scientists' credibility is relative because each individual has unique values and views of the nature of science and objectivity. Through a collaborative policymaking process, citizens and scientists should develop shared values and visions to reconstruct a temporary, intersubjective sense of credibility.     

Regional lifelong learning policies and the social vulnerability of young adults in Girona and Vienna

ABSTRACT

This article explores the interface between lifelong learning policies and the definition of social vulnerability of young adults in two regions located within the European Union. Girona comprises a constellation of small towns with important industry, service and hospitality sectors. Vienna is a global city where many key international operators are based and employ a large number of highly qualified professionals. The article explores to what extent the meta-governance and the ‘causal narratives’ of lifelong learning policies contribute towards shaping the prevailing images of youth vulnerability in these regions. In Girona, bureaucratic governance patterns lifelong learning policies, which strongly rely on the potential of career guidance to encourage the youth to undertake further education. Correspondingly, policy designs and professional discourses emphasise that the beneficiaries previously failed at school. In Vienna, authorities govern lifelong learning by means of both bureaucracy and complex networks of employers and non-profit organisations. The ‘causal narrative’ of the policies straightforwardly claims that all youth must have an experience with employment, whether in apprenticeships or in transitional workshops that emulate real jobs. There, policies portray beneficiaries according to their capacity to undertake and finish apprenticeships.     

科研信息化基础设施的大数据挑战

首先探讨大数据科学（Big Data Science）给现代和未来科研数据基础设施（SDI）带来的挑战,并参考不 同科研团体的工作对数据管理、访问控制和安全要求进行定义,然后介绍科研数据生命周期管理（SDLM）模型,分析 所有的主要阶段,反映现代e-Science的数据管理特性,提出SDI 通用架构模型,为利用现代技术和最佳实践构建以互 用性数据或项目为中心的SDI 奠定了基础,最后对如何利用基于云的现代基础设施服务配置模型顺利实现文中提出的 SDLM和SDI 模型进行阐述,解决SDI 资源的联合访问控制问题,为科研团体提供了一种灵活的访问控制和身份管理模 型。     

Constructivism: Defense or a Continual Critical Appraisal A Response to Gil-Pérez et al.

This commentary is a critical appraisal of Gil-Pérez et al.'s (2002) conceptualization of constructivism. It is argued that the following aspects of their presentation are problematic: (a) Although the role of controversy is recognized, the authors implicitly subscribe to a Kuhnian perspective of `normal' science; (b) Authors fail to recognize the importance of von Glasersfeld's contribution to the understanding of constructivism in science education; (c) The fact that it is not possible to implement a constructivist pedagogy without a constructivist epistemology has been ignored; and (d) Failure to recognize that the metaphor of the `student as a developing scientist' facilitates teaching strategies as students are confronted with alternative/rival/conflicting ideas. Finally, we have shown that constructivism in science education is going through a process of continual critical appraisals.     

Metabolic cost of stride rate, resistance, and combined use of arms and legs on the elliptical trainer

We measured the effects of stride rate, resistance, and combined arm-leg use on energy expenditure during elliptical trainer exercise and assessed the accuracy of the manufacturer's energy expenditure calculations. Twenty-six men and women (M age = 29 years, SD = 8; M body weight = 73. 0 kg, SD = 15.2) participated. Twenty-two participants performed two tests, one without the arm poles (leg-only) and the other with arm poles (combined arm-leg). The other 4 participants performed one test without the arm poles. Both tests consisted of six 5-min stages (two stride rates, 110 and 134 stridesmin-1, and three resistance settings: 2, 5, and 8). Steady-state oxygen uptake (VO2), minute ventilation (VE), heart rate (HR) and rating of perceived exertion (RPE) were measured. Repeated measures analysis of variance determined higher (p <. 001) VO2, VE, and RPE, but not HR, during combined arm-leg versus leg-only exercise at any given intensity. Increases in stride rate and resistance increased VO2, VE, RPE, and HR with the greatest effect on VE and HR from Levels 5 to 8. The manufacturer's calculated energy expenditure was overestimated during both tests. Although the oxygen cost for elliptical trainer exercise was calculated to be approximately 0.1 mlxkg(-1) per stride and 0.7 mlxkg(-1) min-1 per resistance level, VO2 varied widely among individuals, possibly due to differences in experience using the elliptical trainer gender, and body composition. The elliptical trainer offers (a) a variety of intensities appropriate for most individuals and (b) both arm and leg exercise. Due to the wide variability in VO2, predicting the metabolic cost during elliptical trainer exercise for an individual is not appropriate.     

Optimal stabilization for differential systems with delays - Malkin’s approach

The paper considers a process controlled by a system of delayed differential equations. Under certain assumptions, a control function is determined such that the zero solution of the system is asymptotically stable and, for an arbitrary solution, the integral quality criterion with infinite upper limit exists and attains its minimum value in a given sense. To solve this problem, Malkin’s approach to ordinary differential systems is extended to delayed functional differential equations, and Lyapunov’s second method is applied. The results are illustrated by examples, and applied to some classes of delayed linear differential equations.