Suchergebnisse

A discussion of challenges related to the modeling and control of greenhouse crop growth, this book presents state-of-the-art answers to those challenges. The authors model the subsystems involved in successful greenhouse control using different techniques and show how the models obtained can be exploited for simulation or control design; they suggest ideas for the development of physical and/or black-box models for this purpose.Strategies for the control of climate- and irrigation-related variables are brought forward. The uses of PID control and feedforward compensators, both widely used in commercial tools, are summarized. The benefits of advanced control techniques-event-based, robust, and predictive control, for example-are used to improve on the performance of those basic methods.A hierarchical control architecture is developed governed by a high-level multiobjective optimization approach rather than traditional constrained optimization and artificial intelligence techniques. Reference trajectories are found for diurnal and nocturnal temperatures (climate-related setpoints) and electrical conductivity (fertirrigation-related setpoints). The objectives are to maximize profit, fruit quality, and water-use efficiency, these being encouraged by current international rules. Illustrative practical results selected from those obtained in an industrial greenhouse during the last eight years are shown and described. The text of the book is complemented by the use of illustrations, tables and real examples which are helpful in understanding the material.Modeling and Control of Greenhouse Crop Growthwill be of interest to industrial engineers, academic researchers and graduates from agricultural, chemical, and process-control backgrounds.

PurposeThe use of economic sanctions has grown dramatically in recent decades. Nevertheless, many arguments are presented in the public policy space regarding their effects on target populations. The author presents the first systematic analysis of the effects of sanctions on living conditions in target countries.Design/methodology/approachThis paper provides a comprehensive survey and assessment of the literature on the effects of economic sanctions on living standards in target countries. The author identifies 31 studies that apply quantitative econometric or calibration methods to cross-country and national data to assess the impact of economic sanctions on indicators of human and economic development. The author provides in-depth discussions of three sanctions episodes—Iran, Afghanistan and Venezuela—that illustrate the channels through which sanctions affect living conditions in target countries.FindingsOf the 31 studies, 30 find that sanctions have negative effects on outcomes ranging from per capita income to poverty, inequality, mortality and human rights. The author provides new results showing that 54 countries—27% of all countries and 29% of the world economy— are sanctioned today, up from only 4% of countries in the 1960s. In the three cases discussed, sanctions that restricted the access of governments to foreign exchange limited the ability of states to provide essential public goods and services and generated substantial negative spillovers on private sector and nongovernmental actors.Originality/valueThis is the first literature survey that systematically assesses the quantitative evidence on the effect of sanctions on living conditions in target countries.

La violencia social en Venezuela y América Latina, es un fenómeno crónico, pero en los tiempos actuales se ha exacerbado. Durante el siglo XIX hubo violencia de caudillos militares y civiles pero hoy, en tiempos de paz, ha adquirido una morfología esencialmente social. Ella es el producto, parcialmente, de políticas de orientación civil y militar que dieron al traste con el estado benefactor y con las expectativas de realización social. Políticas populistas, desarrollistas, neo-desarrollistas y neoliberales que agravaron las situaciones de crisis y que finalmente rompieron con el consenso social generando condiciones para la violencia social; sobre todo de índole delictiva. ; Social violence in Venezuela and Latin America: crisis of a model of social realization. Social violence in Venezuela and Latin America, is chronic, but in modern times has been exacerbated.Throughout the nineteenth century there was violence of military and civilian leaders but today, in times of peace, it has acquired a nessentially social morphology. It is product, partially, of policies implemented by all states of military nature. Populist policies, developmentalist, socialist, Neo-liberal and neo-developmentalist which have aggravated the crisis and they have finally broken the social consensus, the welfare state and social achievement expectation creating situations conducive to social violence; especially criminal nature.

Social violence in Venezuela and Latin America is a chronic phenomenon, but has exacerbated in the current times. During the 19th century, military and civilian cashions were violent, but today, in times of peace, it has acquired an essentially social morphology. It is the product, in part, of civil-military oriented policies that led to a negative situation and expectations of social fulfilment. Populist, developmental, neo-developmental and neoliberal policies which aggravated crisis situations and eventually broke with social consensus, creating conditions for social violence; above all of a criminal nature. ; Social violence in Venezuela and Latin America: crisis of a model of social realization. Social violence in Venezuela and Latin America, is chronic, but in modern times has been exacerbated.Throughout the nineteenth century there was violence of military and civilian leaders but today, in times of peace, it has acquired a nessentially social morphology. It is product, partially, of policies implemented by all states of military nature. Populist policies, developmentalist, socialist, Neo-liberal and neo-developmentalist which have aggravated the crisis and they have finally broken the social consensus, the welfare state and social achievement expectation creating situations conducive to social violence; especially criminal nature. ; Social violence in Venezuela and Latin America is a chronic phenomenon, but has exacerbated in the current times. During the 19th century, military and civilian cashions were violent, but today, in times of peace, it has acquired an essentially social morphology. It is the product, in part, of civil-military oriented policies that led to a negative situation and expectations of social fulfilment. Populist, developmental, neo-developmental and neoliberal policies which aggravated crisis situations and eventually broke with social consensus, creating conditions for social violence; above all of a criminal nature. ; La violencia social en Venezuela y América Latina, es un ...

El objetivo de estas reflexiones es plantear el problema de la pobreza como un fenómeno de violencia que se manifiesta como violencia estructural en el proceso de exclusión de grandes sectores de la población de las posibilidades de acceder a los bienes sociales y culturales que ofrece el sistema social. Para ello se hizo un análisis de múltiples referencias documentales y una aproximación hermeneútica al texto de la realidad social contemporánea. Finalmente podemos decir que el fenómeno que conforma la pobreza plantea un problema un enfoque de simplicidad sino el de un abordaje de complejidad.