815 resultados para change in working process
Resumo:
The increasing economic competition drives the industry to implement tools that improve their processes efficiencies. The process automation is one of these tools, and the Real Time Optimization (RTO) is an automation methodology that considers economic aspects to update the process control in accordance with market prices and disturbances. Basically, RTO uses a steady-state phenomenological model to predict the process behavior, and then, optimizes an economic objective function subject to this model. Although largely implemented in industry, there is not a general agreement about the benefits of implementing RTO due to some limitations discussed in the present work: structural plant/model mismatch, identifiability issues and low frequency of set points update. Some alternative RTO approaches have been proposed in literature to handle the problem of structural plant/model mismatch. However, there is not a sensible comparison evaluating the scope and limitations of these RTO approaches under different aspects. For this reason, the classical two-step method is compared to more recently derivative-based methods (Modifier Adaptation, Integrated System Optimization and Parameter estimation, and Sufficient Conditions of Feasibility and Optimality) using a Monte Carlo methodology. The results of this comparison show that the classical RTO method is consistent, providing a model flexible enough to represent the process topology, a parameter estimation method appropriate to handle measurement noise characteristics and a method to improve the sample information quality. At each iteration, the RTO methodology updates some key parameter of the model, where it is possible to observe identifiability issues caused by lack of measurements and measurement noise, resulting in bad prediction ability. Therefore, four different parameter estimation approaches (Rotational Discrimination, Automatic Selection and Parameter estimation, Reparametrization via Differential Geometry and classical nonlinear Least Square) are evaluated with respect to their prediction accuracy, robustness and speed. The results show that the Rotational Discrimination method is the most suitable to be implemented in a RTO framework, since it requires less a priori information, it is simple to be implemented and avoid the overfitting caused by the Least Square method. The third RTO drawback discussed in the present thesis is the low frequency of set points update, this problem increases the period in which the process operates at suboptimum conditions. An alternative to handle this problem is proposed in this thesis, by integrating the classic RTO and Self-Optimizing control (SOC) using a new Model Predictive Control strategy. The new approach demonstrates that it is possible to reduce the problem of low frequency of set points updates, improving the economic performance. Finally, the practical aspects of the RTO implementation are carried out in an industrial case study, a Vapor Recompression Distillation (VRD) process located in Paulínea refinery from Petrobras. The conclusions of this study suggest that the model parameters are successfully estimated by the Rotational Discrimination method; the RTO is able to improve the process profit in about 3%, equivalent to 2 million dollars per year; and the integration of SOC and RTO may be an interesting control alternative for the VRD process.
Resumo:
This study investigates a new way of assessing change in psychotherapy, with the goal of decreasing the schism in the field of psychology between research and clinical practice. Change in psychotherapy was assessed in clients presenting with depressive symptoms who were seeking therapy at the Professional Psychology Center (PPC) at the University of Denver. Prior to beginning treatment, the subjects completed the Beck Depression Inventory- II (BDI-II) and the Symptom Checklist-90-R (SCL-90), and were also assessed by independent clinicians using the Shedler-Westen Assessment Procedure II (SWAP-II). Six to nine months later, after completing at least 12 psychotherapy sessions (range 12-21 sessions), the assessment procedure was repeated.There were no significant differences pre- to post-treatment on any measure. However, two subjects in the sample appeared to benefit from treatment, as assessed by both the self-report measures and the SWAP-II. The findings for these two subjects suggest that the SWAP-II can provide a greater depth of understanding about what can change in therapy than self-report measures alone. Possible reasons for the lack of treatment effects in the larger sample are discussed.
Resumo:
Research on the stability of attachment representations across the lifespan has led to two alternative perspectives: the prototype and revisionist perspectives (Fraley, 2002). The prototype perspective posits that there is a stable factor underlying fluctuations in representations and the revisionist perspective argues that there is no inherently stable factor. The current study employed a latent trait-state model to investigate these alternative models of stability and change in representations of romantic relationships in adolescence and young adulthood. The study also sought to identify individual characteristics and relationship experiences that are associated with changes in representations. In a sample of 200 participants, representations were assessed by interview and self-report over seven measurement occasions between ages 15 and 23. Results were consistent with the prototype perspective emphasizing that a stable, latent factor exerts a consistent influence over the lifespan. In addition to a stable component, representations incorporated a component that varies over time. Findings showed that this fluctuating component of representations was associated with internalizing and externalizing symptomatology as well as experiences of support and negative interaction in relationships.
Resumo:
Partnering effectively with families is an important skill for teachers to have to support student achievement, and one that is especially important for early career teachers in order to protect them from burnout and attrition. However, research has demonstrated that teachers do not feel prepared to work with families, and further research is needed to see what difficulties are specific to early career teachers. The following research questions were addressed in the study: 1) What current situation and prior training factors affect early career teachers’ perceptions of efficacy in working with families? 2) Which family-school partnering topics do teachers report the most experience in their prior preparation programs and in their current daily practice? 3) Is there a relationship between number of years reported teaching and overall efficacy scores? 4) What family-school partnering training do early career teachers believe would have been or would be beneficial to receive in their teacher preparation programs versus during their first five years of practice? A survey was created which included a pre-existing self-efficacy scale adapted to reflect family partnering language. This survey was disseminated to 76 first through fifth year Colorado teachers. Results indicate that age of current school placement had a significant effect on overall self-efficacy scale scores, while several other variables had an effect on subscales of the efficacy scale. Recommendations are presented for future research, teacher preparation programs, and school district mentoring.
Resumo:
This paper summarizes the experience gained in dealing with resistance to change appeared in the companies when they develop innovative processes related to the adoption of new technologies, tools, equipment, infrastructure and methodologies. Technological innovation is rapidly absorbed by society on a personal level. But at the enterprise level, resistance to innovation can occur at any hierarchical level of the company and may appear with different intensity. Depending on the type of enterprise, the hierarchical level of the employee, the intensity of resistance and other factors, the measures taken are different. In this paper we summarize our experience in the cataloging of the resistance to innovation in terms of impact on workers and showing how technology education and business training can help overcome these resistance forces. This paper describes the experience acquired over 22 projects deployed in the period 2005 to 2011 and that has affected a total of 264 workers of different cultural, technological, business and hierarchical levels.
Resumo:
In a former publication, we have analyzed the transient neutron star X-ray binary GRO J1008–57 using all available RXTE-, Swift-, and Suzaku-data. As we have found, the source’s spectral components, i.e., a power-law with high exponential cutoff and a black-body, are strongly correlated with the hard X-ray flux (15–50 keV). We update the analytical description of these dependence, including a change in the photon index behaviour from a flat to a logarithmic function. The flux, where the change occurs, is consistent with the onset of the black-body emission. Thus, a change of the accretion state always occurs in GRO J1008–57 at a particular flux level.
Resumo:
Recent advances in statistical downscaling have allowed the reconstruction of temperatures for the complete 1948–2011 period in a spatial resolution of 90 m and without gaps for the Valencian Community (Spain) and bordering areas. It presently enables analyses in this region, which allows the determination of recent temperature changes at subregional and local scales. The present work focuses on obtaining the thermicity index according to Rivas-Martínez, a well-known indicator of different thermotypes associated with bioclimatic horizons. The change in this index, which has happened in the region between 1948 and 2011, was calculated by generating fine-scale maps of the potential extension of different thermotypes. The results show a greater regression for the thermotypes in a finicolous position, e.g. Orotemperate, Supratemperate and Supramediterranean horizons, which herein indicate greater potential vulnerability in climate change. In the absence of, and given the need for, such fine-scale information, this work should be useful for specialized researchers to spatially limit the potentially most vulnerable biotopes to climate change.
Resumo:
v.36:no.5(1950)
Resumo:
The North Caucasus has been the most unstable region of the Russian Federation since the collapse of the Soviet Union. Considering the scale of violence, the conflict in the region should be regarded as a local civil war between the Salafi Islamic armed underground and the secular authorities of the North Caucasus republics, supported by the security services. The Chechen leader Ramzan Kadyrov, who has made himself de facto independent from Moscow, holds a particularly strong position in the region and his ambition is to gain control of the neighbouring territories. The Russian leadership, which sees the security of the Winter Olympics in Sochi as its top priority, is facing a strategic choice between trying to integrate the North Caucasus with the rest of the federation, or isolating the region and accepting the existence of an informal "internal abroad” within Russia. The cultural processes taking place in the region, including Islamisation, de-modernisation and de-Russification, have been driving the North Caucasus ever further away from the rest of Russia, strengthening a mutual sense of foreignness.
Resumo:
Mit dem Ende des 18. Parteitags der Kommunistischen Partei Chinas (KPCh) Mitte November kam auch die erste Phase des chinesische Führungswechsels zum Abschluss. Die wichtigste Aufgabe der Partei während dieser Phase war es, den ständigen Ausschuss des Politbüros, also das oberste beschlussfassende Organ der Partei, zu wählen. Zusätzlich zur Ernennung von sieben Spitzenpolitikern umfasst der Wechsel auch die Wahl eines neuen Politbüros und des Zentralkomitees als Vertretung der 83 Millionen Parteimitglieder.
Resumo:
This paper examines how local communities adapt to climate change and how governance structures can foster or undermine adaptive capacity. Climate change policies, in general, and disaster risk management in mountain regions, in particular, are characterised by their multi-level and multi-sectoral nature during formulation and implementation. The involvement of numerous state and non-state actors at local to national levels produces a variety of networks of interaction and communication. The paper argues that the structure of these relational patterns is critical for understanding adaptive capacity. It thus proposes an expanded concept of adaptive capacity that incorporates (horizontal and vertical) actor integration and communication flow between these actors. The paper further advocates the use of formal social network analysis to assess these relational patterns. Preliminary results from research on adaptation to climate change in a Swiss mountain region vulnerable to floods and other natural hazards illustrate the conceptual and empirical significance of the main arguments.